Wireless communication methods and apparatus supporting peer to peer communications

ABSTRACT

A first mobile node supports peer to peer communications but not cellular communications. Other mobile modes in the communication system support a cellular mode and may support a peer to peer communications mode. The communications system is such that spectrum may be dynamically reallocated between being designated to be used for peer to peer operations and being used primarily for cellular network based operations. Beacon signals are used to communicate a current mode of frequency spectrum usage designation. The first mobile node, being in an ongoing peer to peer communications session detects that the spectrum is being reallocated for cellular based operations. The first mobile node reduces its transmission power level in response to the detected spectrum reallocation. In some embodiments, the first mobile is allowed to continue its ongoing peer to peer session while the spectrum is primarily allocated for cellular communications, albeit at a lower transmission power level.

RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/758,011 filed on Jan. 11, 2006, titled “METHODSAND APPARATUS FOR USING BEACON SIGNALS FOR IDENTIFICATION,SYNCHRONIZATION OR ACQUISITION IN AN AD HOC WIRELESS NETWORK”, U.S.Provisional Patent Application Ser. No. 60/738,010 filed on Jan. 11,2006, titled “METHODS AND APPARATUS FOR FACILITATING IDENTIFICATION,SYNCHRONIZATION OR ACQUISITION USING BEACON SIGNALS”, U.S. ProvisionalPatent Application Ser. No. 60/758,012 filed on Jan. 11, 2006, titled“METHODS AND APPARATUS FOR USING BEACON SIGNALS IN A COGNITIVE RADIONETWORK”, U.S. Provisional Patent Application Ser. No. 60/863,304 filedon Oct. 27, 2006, U.S. Provisional Patent Application Ser. No.60/845,052 filed on Sep. 15, 2006, and U.S. Provisional PatentApplication Ser. No. 60/845,051 filed on Sep. 15, 2006, each of which ishereby incorporated by reference and all of which are assigned to theassignee hereof.

FIELD

The present invention is directed to methods and apparatus for signalingin wireless communication and, more particularly, to methods andapparatus for using signals for identification, synchronization and/oracquisition.

BACKGROUND

In a wireless network, e.g., an ad hoc network in which a networkinfrastructure does not exist, a terminal has to combat certainchallenges in order to set up a communication link with another peerterminal. One challenge is to make the terminals in the vicinity to besynchronized to a common timing and/or frequency reference. A commontiming and/or frequency reference is crucial for the terminals toestablish communication links. For example, in an ad hoc network, when aterminal just powers up or moves into a new area, the terminal may haveto first find out whether another terminal is present in the vicinitybefore any communication between the two terminals can start. Thegeneral solution is to let the terminal transmit and/or receive signalsaccording to certain protocol. However, if the terminals do not have acommon timing notation, it is possible that when a first terminal istransmitting a signal and a second terminal is not in the receivingmode, the transmitted signal does not help the second terminal to detectthe presence of the first terminal.

In view of the above discussion, it should be appreciated that there isa need for new and improved ways for identification, acquisition, and/orsynchronization, especially in a wireless system in which the networkinfrastructure may not be available.

SUMMARY

Various embodiments are directed to methods and apparatus in which awireless terminal performs transmission power level adjustments as afunction of determined frequency band primary usage designationinformation. In some embodiments, a wireless terminal communicating aspart of a peer to peer communications session while the spectrum isdesignated to be used for peer to peer communications, is allowed tocontinue with its ongoing peer to peer communications session followingdynamic reallocation of the frequency spectrum to be used primarily forcellular access node based communications, albeit at a reduced powerlevel. This feature can be particularly advantageous for wirelessterminals which support peer to peer communications, but do not supportcellular based communications.

An exemplary method of operating a wireless device comprises:determining from a first broadcast signal received from a base stationthat a frequency band corresponding to said base station is being usedfor peer to peer communications; determining from a second broadcastsignal received from the base station that said frequency band has beenchanged to being used as a cellular frequency band, and in response todetermining that the frequency band is being used as a cellularfrequency band reducing transmission power. An exemplary wirelesscommunications device, e.g., mobile node, which supports peer to peercommunications, comprises: a receiver for receiving signals includingbroadcast signals; a transmitter for transmitting user data as part of apeer to peer communications session; a mode determination module fordetermining based on received broadcast signals a mode of communicationsband operation, the mode of communications band operation indicating amode of operation in which said frequency band is to be used at a pointin time, the determined mode of communications band operation being oneof a plurality of frequency band modes including at least a cellularcommunications mode and a first peer to peer communications mode; and amode control module for controlling wireless communications deviceoperation as a function of at least one of a mode determination and achange in a determined mode of communications band operation, said modecontrol module controlling the transmitter to reduce transmission powerin response to determining that the frequency band is to be used as acellular frequency band.

While various embodiments have been discussed in the summary above, itshould be appreciated that not necessarily all embodiments include thesame features and some of the features described above are not necessarybut can be desirable in some embodiments. Numerous additional features,embodiments and benefits are discussed in the detailed description whichfollows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary communications system supporting bothaccess node based communications and peer to peer communicationsimplemented in accordance with various embodiments.

FIG. 2 illustrates two exemplary spectrum bands available to be used ina geographic area.

FIG. 3 illustrates a ladder diagram of an exemplary method of obtainingand utilizing spectrum information implemented in accordance withvarious embodiments.

FIG. 4 illustrates an example of utilizing timing synchronizationinformation implemented in accordance with various embodiments.

FIG. 5 illustrates an exemplary diagram of receiving paging and being ina peer-to-peer or TDD session implemented in accordance with variousembodiments.

FIG. 6 illustrates a flowchart of an exemplary method of operating awireless terminal to determine data rates corresponding to potentiallinks with alternative nodes, e.g., a base station and a peer wirelessterminal, and selecting a node to communicate with in accordance withvarious embodiments.

FIG. 7 illustrates a ladder diagram of an exemplary method of usingbeacon and/or broadcast channels to temporarily convert infrastructurespectrum band for non-infrastructure based service implemented inaccordance with various embodiments.

FIG. 8 illustrates two exemplary ad hoc networks in two geographic areasimplemented in accordance with various embodiments.

FIG. 9 illustrates exemplary spectrum bands available to be used in twodifferent geographic areas.

FIG. 10 illustrates exemplary system beacon signals transmitted in thead hoc networks in two different geographic areas.

FIG. 11 illustrates an exemplary wireless terminal implemented inaccordance with various embodiments.

FIG. 12 comprising the combination of FIG. 12A and FIG. 12B is a drawingof a flowchart of an exemplary method of operating a wireless terminalto communicate with another communications device in accordance withvarious embodiments.

FIG. 13 is a drawing of an exemplary wireless terminal, e.g., mobilenode, implemented in accordance with various embodiments.

FIG. 14 is a drawing of a of a flowchart of an exemplary method ofoperating a wireless terminal which supports both peer to peercommunications and communications with a base station in accordance withvarious embodiments.

FIG. 15 is a drawing of an exemplary wireless terminal, e.g., mobilenode, implemented in accordance with various embodiments.

FIG. 16 is a drawing of a flowchart of an exemplary method of operatinga base station in accordance with various embodiments.

FIG. 17 is a drawing of an exemplary base station in accordance withvarious embodiments.

FIG. 18 is a drawing of an exemplary beacon signal transmissionapparatus in accordance with various embodiments.

FIG. 19 is a drawings of a flowchart of an exemplary method of operatinga beacon signal transmitter device in accordance with variousembodiments.

FIG. 20 comprising the combination of FIG. 20A and FIG. 20B is a drawingof a flowchart of an exemplary method of operating a base station inaccordance with various embodiments.

FIG. 21 is a drawing of an exemplary base station in accordance withvarious embodiments.

FIG. 22 is a drawing of a flowchart of an exemplary method of operatinga wireless device, e.g., a mobile node, in accordance with variousembodiments.

FIG. 23 is a drawing of an exemplary wireless terminal e.g., mobile nodein accordance with various embodiments.

FIG. 24 is a drawing of a flowchart of an exemplary method of operatinga mobile communications device in a system including a base station inaccordance with various embodiments.

FIG. 25 is a drawing of an exemplary wireless terminal, e.g., mobilenode, in accordance with various embodiments.

FIG. 26 is a drawing of a flowchart of an exemplary method of operationa wireless device, e.g., a mobile node, in accordance with variousembodiments.

FIG. 27 is a drawing of an exemplary wireless terminal, e.g., mobilenode, implemented in accordance with various embodiments.

FIG. 28 comprising the combination of FIG. 28A and FIG. 28B is a drawingof a flowchart of an exemplary communications method in accordance withvarious embodiments.

FIG. 29 is a drawing of an exemplary wireless terminal, e.g., mobilenode, in accordance with various embodiments.

FIG. 30 is a drawing of an exemplary communications system in accordancewith various embodiments.

FIG. 31 is a drawing of an exemplary wireless communications systemwhich supports both peer to peer communications and cellularcommunications in accordance with various embodiments.

FIG. 32 is a drawing illustrating exemplary beacon burst time positionhopping in accordance with various embodiments.

FIG. 33 is a drawing illustrating exemplary beacon burst time positionhopping and beacon symbol tone hopping in accordance with variousembodiments.

FIG. 34 is a drawing illustrating exemplary coordinated timing in a peerto peer communications band in accordance with various embodiments.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary communications system 100 supportingboth access node based communications and peer to peer communicationsimplemented in accordance with various embodiments. An infrastructurebase station 108 is coupled with a big network, e.g., the Internetthrough a network node 110 via a wired link 111. The base station 108provides services to the wireless terminals, such as a first wirelessterminal 102 and a second wireless terminal 104, in the geographic area106 via a wireless spectrum band. The wireless spectrum band is calledthe infrastructure band.

In addition to the infrastructure band, a different spectrum band,referred to as non-infrastructure band may also be, and sometimes is,available to be used by the wireless terminals in the same geographicarea. Thus wireless terminals (102, 104) can participate in an ad hocpeer to peer communication session using non-infrastructure band. FIG. 2includes drawing 200 which illustrates the notion of the infrastructureband 202 and the non-infrastructure band 204. The two bands are in someembodiments non-overlapping. In a typical embodiment, the infrastructureband includes a pair of FDD (frequency, division duplex) spectrum bandsor an unpaired TDD (time division duplex) spectrum band. Thenon-infrastructure band includes an unpaired spectrum and can be usedfor ad hoc peer-to-peer communication. In some embodiments, thenon-infrastructure band is also used for TDD. In some embodiments, thesame infrastructure base station, which provides the service in theinfrastructure band, may also provide service in the non-infrastructureband.

In an exemplary embodiment, the infrastructure base station transmits abeacon signal in the infrastructure band. The beacon signal is a specialsignal that occupies a small fraction of the total minimum transmissionunits in the available spectrum. In some embodiments, a beacon signalincludes a sequence of one or more beacon signal bursts, each beaconsignal burst including at least one beacon symbol. In some embodiments,the beacon symbols, corresponding to a beacon signal occupy a smallfraction, e.g., in some embodiments no more than 0.1%, of the totalminimum transmission units in the available spectrum air link resource.A minimum transmission unit is the minimum unit of air link resource touse for communication. In some exemplary frequency division multiplexingsystems, e.g., some OFDM systems, a minimum transmission unit is asingle tone over a symbol transmission period, sometimes referred to asa tone-symbol. In addition, the average transmission power of the beaconsymbols of the beacon signal is much higher, e.g., at least 10 dBs or atleast 16 dB higher, than the average transmission power of data andcontrol signals per minimum transmission unit when the terminaltransmitter is in an ordinary data session.

In addition, the infrastructure base station, in some embodiments, usesa broadcast channel, including the beacon signal, to send the systeminformation including the frequency (e.g., carrier) location of thenon-infrastructure spectrum band an/or the type of service provided inthe band, e.g., TDD (time division duplex) or ad hoc networking.

FIG. 3 illustrates an exemplary ladder diagram 300 of an exemplarymethod of obtaining and utilizing spectrum information implemented by awireless terminal in accordance with various embodiments. Drawing 300includes time axis 301, infrastructure base station 302 and wirelessterminal 304.

The wireless terminal 304 knows the frequency location of theinfrastructure spectrum band. The wireless terminal 304 first tunes tothe infrastructure spectrum band (306) and searches for the beaconsignal (308) to find the availability of the infrastructure basestation. The infrastructure base station 302 transmits beacon signal 310which is received and detected (312) by wireless terminal 304. Once thewireless terminal 304 detects the beacon signal (310), the wirelessterminal 304 synchronizes (314) itself with the infrastructure basestation 302. The infrastructure base station 302 transmits broadcastsignals 316, in addition to beacon signals 310. In some embodiments,wireless terminal 304 further receives the broadcast signals 316 andrecovers system information from a broadcast channel to obtain thefrequency location information of the non-infrastructure spectrum band(318). The wireless terminal 304, in various embodiments, derives timingand/or frequency information from at least one of the broadcast channelsand/or the beacon signal (320). The wireless terminal 304 then tunes tothe frequency location of the non-infrastructure band to obtain the TDDand/or ad hoc service (322). The wireless terminal 304 uses the timingand/or frequency information derived in step 320 when the terminal 304obtains the service in the non-infrastructure band (324).

Unlike the infrastructure band, the non-infrastructure band may not, andsometimes does not, have a natural source from which each of thewireless terminals can derive synchronization information. When each ofthe wireless terminals use the timing and/or frequency informationderived from a common source, i.e., the infrastructure base station inthe infrastructure spectrum band, the wireless terminals now have acommon timing and/or frequency reference. Advantageously this enablessynchronization of the terminals in the non-infrastructure band. Toelaborate, drawing 400 of FIG. 4 illustrates an example of utilizingtiming synchronization information obtained from infrastructuresignaling in an associated non-infrastructure band.

The horizontal axis 401 represents time. The infrastructure base stationtransmits the beacon signal 402 in the infrastructure band. The beaconsignal 402 includes a sequence of beacon signal bursts, 404, 406, 408,and so on. Suppose that two wireless terminals derive the timinginformation from the beacon signal 402, and then time to thenon-infrastructure band, which is used for peer-to-peer ad hoc network.

Either of the two wireless terminals has to be aware of the presence ofthe other before they can set up a peer-to-peer communication session.In one embodiment, either wireless terminal transmits or receives a userbeacon signal burst in the non-infrastructure band in a time interval,which is a function of the timing of the beacon signal bursts sent bythe infrastructure base station.

For example, in FIG. 4, the time interval starts from a time instancethat has known time offset 410 from the beginning, 412 of a beaconsignal burst sent by the infrastructure base station. Either wirelessterminal in some embodiments randomly chooses whether to transmit orreceive. In the exemplary scenario shown in FIG. 4, the first wirelessterminal chooses to transmit, as indicated by exemplary user beaconsignal burst 414 transmitted into the non-infrastructure spectrum band,while the second wireless terminal chooses to receive. The secondwireless terminal controls its receiver on time interval for beaconmonitoring in the non-infrastructure spectrum band such as to includeinterval 416 corresponding to the first wireless terminals beacontransmission, and the second wireless terminal detects the user beaconsignal sent by he first wireless terminal. The second wireless terminalmay, and sometimes does, then start to establish a communication linkwith the first wireless terminal. However, if both wireless terminalschoose to transmit or to receive, then they may not find each other inthis time interval. The wireless terminals can probabilistically findeach other in subsequent time intervals.

Note that in the absence of the common timing reference, the wirelessterminals may have to be in the listening mode in a much longer timeinterval in order to detect a user beacon signal burst. The commontiming reference thus helps the wireless terminals to find each othermuch more rapidly and in a more power efficient manner.

In another embodiment, the base station additionally transmits thebeacon, signal in the second spectrum band, so that if the wirelessterminal directly tunes to the second spectrum band, the wirelessterminal can derive the desired common timing and/or frequency referencefrom the beacon signal.

FIG. 5 illustrates an exemplary state diagram 500 of receiving pagingand being in a peer-to-peer or TDD session implemented in accordancewith various embodiments. Operation starts in step 501, where thewireless terminal is powered on and initialized and then proceeds tostep 502.

A wireless terminal and the network paging agent, e.g., a server on thenetwork side, have an agreement on when a page for the wirelessterminal, if any, will be sent to the wireless terminal via theinfrastructure base station. The wireless terminal sets a timer tomonitor potential incoming pages (502). In a typical paging system, thewireless terminal may go to a power saving mode until the timer expires.In accordance with a novel feature of various exemplary embodiments, thewireless terminal tunes to the non-infrastructure spectrum band andobtains service (504), e.g., TDD or peer-to-peer communication service.When the timer expires, the wireless terminal tunes to theinfrastructure spectrum band and monitors a paging channel (506). If theterminal is not paged, the wireless terminal may set the timer again forthe next page monitoring time (502). Otherwise, the wireless terminal isbeing paged, needs to process the received page, and processes thereceived page (508).

In some embodiments, there is a common time interval during which eachof the wireless terminals or a large subset of the wireless terminalsusing the non- infrastructure spectrum band suspend the sessions in thenon-infrastructure spectrum band and check pages in the infrastructurespectrum band. Advantageously, this synchronized suspension ofnon-infrastructure sessions helps reduce the wastage of resource in thenon-infrastructure band.

FIG. 6 illustrates a flowchart 600 of an exemplary method of operating awireless terminal to determine data rates corresponding to potentiallinks with alternative nodes, e.g. a base station and a peer wirelessterminal, and selecting a node to communicate with in accordance withvarious embodiments.

A base station transmits a beacon signal. In some embodiments, in thenon-infrastructure band, the infrastructure base station transmits abeacon signal, and a wireless terminal also transmits a user beaconsignal. Thus, in such an embodiment, a wireless terminal can have itsreceiver tuned to the non-infrastructure band and receive base stationbeacon signals and wireless terminal user beacon signals. Differentbeacon signals, in some embodiments., differentiate from each other byusing different beacon tone hopping sequences and/or different timing ofbeacon bursts. A transmitter, e.g., the base station or the wirelessterminal, in some embodiments is also used to transmit data/controlchannels. In accordance with various embodiments, the transmission powerof the beacon signal and/or that of the data/control channels are suchthat from the received beacon signal or signals, a receiver can predictthe signal quality of the data/control channels, and/or compare thesignal quality from multiple transmitters.

In some embodiments, the transmission power of the base station beaconsignal is the same for each base station. In some embodiments, thetransmission power of the user beacon signal is the same for each of thewireless terminals transmitting user beacon signals. In someembodiments, the transmission power of base station and user beacons arethe same. In some embodiments, the data/control channels are sent at atransmission power, which is a function of the transmission power of thebeacon signal. For example, the per minimum transmission unittransmission power of the data channel, at a given coding and modulationrate, is a fixed dB amount, e.g., 10 dBs or 16 dBs, below thetransmission power of the beacon signal.

With regard to FIG. 6, operation, of the exemplary method starts in step601, where the wireless terminal is powered on and initialized andproceeds to step 602 for each link being considered. In step 602 thewireless terminal receives a beacon signal from a transmitter, e.g., aninfrastructure base station transmitter or a wireless terminaltransmitter, and then, in step 604 the wireless terminal measures thereceived power. Operation proceeds from step 604 to step 606. In step606, the wireless terminal then predicts the received power of user datasignals, e.g., a data/control traffic channel, assuming that thewireless terminal is receiving the channel from the transmitter, usingthe known power relationship between the traffic channel and the beaconsignal. In step 608, the wireless terminal further measures thebackground noise and interference. Then, in step 610, the wirelessterminal predicts the signal quality, e.g., signal-to-noise ratio (SNR)of a data session if the wireless terminal is to set up a session withthe device, e.g., base station or wireless terminal, corresponding tothe transmitter, and sees whether the signal quality and thus the datarate of the data session are sufficient. In some cases, the wirelessterminal may, and sometimes does, receive beacon signals from multipletransmitters. In step 611, the wireless terminal compares the signalquality from those transmitters considered and selects a proper one withwhich to communicate, thus selecting the base station or wirelessterminal corresponding to the selected transmitter.

FIG. 7 illustrates a ladder diagram 700 of an exemplary method of usingbeacon and/or broadcast channels to temporarily convert infrastructurespectrum band for non-infrastructure based service implemented inaccordance with various embodiments. Unlike some of the otherembodiments presented, this exemplary embodiment has an infrastructureband but does not need a fixed non-infrastructure band.

The vertical axis 702 represents time. The infrastructure base station704 checks (708) whether there is any wireless terminal using the normalservice provided by the infrastructure base stations such as normal FDDor TDD service. The normal service is referred to as infrastructurebased service. If the answer is no, then the infrastructure base stationcan convert (710) the infrastructure spectrum band to become anon-infrastructure band, which can be used by non-infrastructure basedservice, such as peer-to-peer communication service. To do so, the basestation sends at least one of a beacon signal (712) and a non-beaconbroadcast signal (714) to indicate, that the infrastructure band hasbeen converted to non-infrastructure band. Upon the reception of thatsignal, the wireless terminals, e.g., wireless terminal 706, in the areacan start to use non-infrastructure service in the band (716).

At a later time, the infrastructure base station 704 may decide (718) toreturn the spectrum band to the infrastructure based service. Theinfrastructure base station in some embodiments does so because of atleast one of the following reasons: 1) the infrastructure base stationsenses that some wireless terminals may need the infrastructure basedservice; 2) some timer has expired, in which case the timer is used tocontrol the time duration of the infrastructure spectrum band being usedas a non-infrastructure band. To do so, the base station 704 sends atleast one of a beacon signal (720) and a non-beacon broadcast signal(722) to indicate that the infrastructure band has returned to theinfrastructure based service. Upon the reception of that signal thewireless terminals in the area, e.g., wireless terminal 706, can ceaseto use non-infrastructure service in the band (724). For example, if awireless terminal has an on-going peer-to-peer communication session,the wireless terminal shall stop or suspend the session.

FIG. 8 illustrates in drawing 800 two exemplary ad hoc networks (801,851) in two graphic areas (806, 856), respectively implemented inaccordance with various embodiments.

The ad hoc network 801 in geographic area A 806 includes a number ofterminals, such as a first wireless terminal 802 and a second wirelessterminal 804, and a special transmitter 808, which transmits a systembeacon signal in accordance with the exemplary embodiment. The wirelessterminals, in some embodiments use the system beacon signal as a systemreference signal. The special transmitter in some, embodiments iscoupled to a big network, e.g., the Internet, through a network node810, e.g., via a wired link. The special transmitter 808, in someembodiments, is also used to have peer-to-peer sessions with a wirelessterminal. Alternatively, in some embodiments the transmitter may be, andsometimes is a standalone unit.

The ad hoc network 851 in geographic area B 856 includes a number ofterminals, such as a third wireless terminal 852 and a fourth wirelessterminal 854, and a special transmitter 858, which transmits a systembeacon signal in accordance with the exemplary embodiment. The specialtransmitter in some embodiments is coupled to a big network, e.g., theInternet, through a network node 860 e.g., via a wired link.

In this exemplary embodiment, the spectrum availability is a function ofthe environment. Here, infrastructure spectrum bands may not exist. Forexample, drawing 900 of FIG. 9 shows exemplary spectrum bands availablein geographic area A 806 and in geographic area B 856. Those spectrumbands are non-infrastructure.

The horizontal axis 905 represents frequency. The upper portion 901 ofthe FIG. 9 shows that there are two spectrum bands, 902 and 904,available for use in the ad hoc network 801 in geographic area A 806.The lower portion 903 of FIG. 9 shows that there are two spectrum bands,906 and 908, available for use in the ad hoc network 851 in geographic,area B 856. In the exemplary scenario shown in FIG. 9, the spectrumbands 904 and 908, are identical. In other words, part of the spectrumbands available in area A and area B (904 and 908) are the same, whilethe rest (902 and 906) are different.

One reason that a different set of spectrum bands are available in adifferent area is that a spectrum band may have been allocated to otherservices in some geographic area but can be made available in anotherarea. When a wireless terminal moves into area A or area B, the wirelessterminal needs to first figure out which spectrum bands are availablefor use, so that the wireless terminal does not cause interference ordisruption to existing services.

To help the wireless terminal to figure out the spectrum availability ina given area, in accordance with a feature of some embodiments, aspecial transmitter transmits a system beacon signal in each of thespectrum bands that are available for use in the vicinity of thegeographical area in which the special transmitter is located. Thebeacon signal is a special signal that occupies a small fraction of thetotal minimum transmission unit in the available spectrum. In someembodiments, the beacon symbols of the beacon signal occupy no more than0.1% of the total minimum transmission units in the available spectrumair link resource. A minimum transmission unit is the minimum unit ofresource to use for communication. In some exemplary frequency divisionmultiplexing systems, e.g., some OFDM systems, a minimum transmissionunit is a single tone over a symbol transmission period, sometimesreferred to as an OFDM tone-symbol. In addition, the transmission powerof the beacon symbols per minimum transmission unit is much higher,e.g., in some embodiments at least 10 dB higher, than the averagetransmission power of data and control signals per minimum transmissionunit when the transmitter is in an ordinary data session. In some suchembodiments, the transmission power of the beacon signal's beaconsymbols per minimum transmission unit is at least 16 dBs higher than theaverage transmission power of data and control signals per minimumtransmission unit when the transmitter is in an ordinary data session.

Drawing 1000 of FIG. 10 illustrates exemplary system beacon signalstransmitted in exemplary, ad hoc networks (801, 851) in two differentgeographic areas (806, 856), respectively. The upper portion 1002illustrates the system beacon signal transmitted by the specialtransmitter 808 in area A 806 and the lower portion 1004 illustrates thesystem beacon signal transmitted by the special transmitter 858 in areaB 856.

In either the upper or the lower portion (1002, 1004), the horizontalaxis 1006 represents frequency and the vertical axis 1008 representstime.

Recall from FIG. 9 that spectrum bands 902 and 904 are available in areaA 806. The upper portion 1002 of FIG. 10 shows that the specialtransmitter 808 transmits the system beacon signal burst 1010 includingbeacon symbol(s) 1012 at time t1 1014 in spectrum band 902, andtransmits the system beacon burst 1016 including beacon symbol(s) 1018at time t2 1020 in spectrum band 904. The transmitter 808 then repeatsthe above procedure and transmits the system beacon signal burst 1022including beacon symbol(s) 1024 at time t3 1026 in spectrum band 902 andtransmits the system beacon signal burst 1028 including beacon symbol(s)1030 at time t4 1032 in spectrum band 904, and so on. In someembodiments, the beacon signal bursts 1010 and 1022 are identical, e.g.,the beacon symbols occupy the same positions in a beacon burst. In someembodiments, the beacon signal bursts 1010, 1022 vary, e.g., thepositions of the beacon symbols(s) change in accordance with apredetermined hopping sequence being implemented by beacon transmitter808. In some the beacon signal bursts 1016 and 1028 are identical. Insome embodiments the beacon signal bursts 1016 and 1028 vary. e.g., inaccordance with a predetermined hopping sequence being implemented bybeacon transmitter 808. In some embodiments, the beacon signal bursts1010 and 1016 are similar, e.g., the beacon symbols occupy the samerelative positions in the beacon burst.

Recall from FIG. 9 that spectrum bands 906 and 908 are available in areaB 856. The lower portion 1004 of FIG. 10 shows that the specialtransmitter 858 transmits the system beacon signal burst 1034 includingbeacon symbol(s) 1036 at time t5 1038 in spectrum band 906 and transmitsthe system beacon signal burst 1040 including beacon symbol(s) 1042 attime t6 1044 in spectrum band 908. The transmitter 858 then repeats theabove procedure and transmits the system beacon signal burst 1046including beacon symbol(s) 1048 at time t7 1050 in spectrum band 906 andtransmits the system beacon signal burst 1052 including beacon symbol(s)1054 at time t8 1056 in spectrum band 908, and so on.

In an exemplary embodiment at a given time, a special transmittertransmits at most one beacon signal burst in a spectrum band. Thespecial transmitter hops across each of the available spectrum bands,successively from one spectrum band to another, and transmits the beaconsignal burst in each band at a given time. For example, in theembodiment shown in FIG. 10, times t1 1014, t2 1020, t3 1026, t4 1032 donot overlap with each other. However it is also possible that in otherembodiments the transmitter may, and sometimes does simultaneouslytransmits multiple beacon signals, each in a different spectrum bands.

In the example of drawing 1000 of FIG. 10, with respect to thetransmitter 808 in area A, t4>t3>t2>t1, and with respect to thetransmitter 858 in area B, t8>t7>t6>t5. However, the drawing does notintend to show that a timing relationship between t5, and t4 exists suchthat t5 is necessarily greater than t4. For example, the range of timeincluding (t1, t2, t3, t4) and the range of time including (t5, t6, t7,t8) may, and sometimes does, at least partially overlap. In someembodiments the two transmitters (808, 858) operate independently fromone another and are not intentionally timing synchronized. In someembodiments, the two transmitters (808, 858) have timing structures,which are coordinated, e.g. synchronized with respect to one another.

FIG. 11 provides a detailed illustration of an exemplary wirelessterminal 1100 implemented in accordance with the present invention. Theexemplary terminal 1100, depicted in FIG. 11, is a detailedrepresentation of an apparatus that may be used as any one of terminals102 and 104 depicted in FIG. 1. In the FIG. 11 embodiment, the wirelessterminal 1100 includes a processor 1104, a wireless communicationinterface module 1130, a user input/output interface 1140 and memory1110 coupled together by bus 1106. Accordingly, via bus 1106 the variouscomponents of the wireless terminal 1100 can exchange informationsignals and data. The components 1104, 1106, 1110, 1130, 1140 of thewireless terminal 1100 are located inside a housing 1102.

The wireless communication interface 1130 provides a mechanism by whichthe internal components of the wireless terminal 1100 can send andreceive signals to/from external devices and another terminal. Thewireless communication interface 1130 includes, e.g., a receiver module1132 and a transmitter module 1134, which are connected with a duplexer1138 with an antenna 1136 used for coupling the wireless terminal 1100to other terminals, e.g., via wireless communications channels.

The exemplary wireless terminal 1100 also includes a user input device1142, e.g., keypad, and a user output device 1144, e.g., display, whichare coupled to bus 1106 via the user input/output interface 1140. Thus,user input/output devices 1142, 1144 can exchange information, signalsand data with other components of the terminal 1100 via userinput/output interface 1140 and bus 1106. The user input/outputinterface 1140 and associated devices 1142, 1144 provide a mechanism bywhich a user can operate the wireless terminal 1100 to accomplishvarious tasks. In particular, the user input device 1142 and user outputdevice 1144 provide the functionality that allows a user to control thewireless terminal 1100 and applications, e.g., modules, programs,routines and/or functions, that execute in the memory 1110 of thewireless terminal 1100.

The processor 1104 under control of various modules, e.g., routines,included in memory 1110 controls operation of the wireless terminal 1100to perform various signaling and processing. The modules included inmemory 1110 are executed on startup or as called by other modules.Modules may exchange data, information, and signals when executed.Modules may also share data and information when executed. In the FIG.11 embodiment, the memory 1110 of wireless terminal 1100 includes asignaling/control module 1112 and signaling/control data 1114.

The signaling/control module 1112 controls processing relating toreceiving and sending signals, e.g., messages, for management of stateinformation storage, retrieval, and processing. Signaling/control data1114 includes state information, e.g., parameters, status and/or otherinformation relating to operation of the wireless terminal. Inparticular, the signaling/control data 1114 includes variousconfiguration information 1116, e.g., the page monitoring interval, thefrequency location of infrastructure spectrum band andnon-infrastructure spectrum band, the timing and/or frequency referenceinformation of the beacon signal received from the infrastructure basestation, and the power relationship between the beacon signal and thedata/control traffic channel. The module 1112 may, and sometimes does,access and/or modify the data 1114, e.g., update the configurationinformation 1116. The module 1112 also includes a module 1113 forreceiving system info and timing info on non-infrastructure band frominfrastructure base station; module 1115 for using system and timinginfo in non-infrastructure band; module 1117 for suspending session innon-infrastructure band and monitoring pages in infrastructure band; andmodule 1119 for predicting signal quality of a data session fromreceived beacon signal power from a transmitter.

FIG. 12 comprising the combination of FIG. 12A and FIG. 12B is aflowchart 1200 of an exemplary method of operating a wireless terminalto communicate with another communications device in accordance withvarious embodiments. Operation starts in step 1202, where the wirelessterminal is powered on and initialized and proceeds to step 1204. Instep 1204, the wireless terminal receives a first signal from a firstcommunications band, said first signal being from a first communicationsdevice which broadcasts on a recurring basis, said first communicationsdevice and said another communications device being differentcommunications devices. Operation proceeds in step 1204 to step 1206.

In step 1206 the wireless terminal determines, based on the firstsignal, a first time interval to be used for transmitting a secondsignal to said another communications device. Then, in step 1208, thewireless terminal determines based on the first signal a second timeinterval to be used for receiving signals from devices other than thefirst communications device. Operation proceeds from step 1208 to step1210.

In step 1210, the wireless terminal derives frequency information fromthe received first signal. Step 1210 includes sub-step 1211 in which thewireless terminal determines a second communications band based on thereceived first signal. Operation proceeds from step 1210 to step 1212 inwhich the wireless terminal derives a parameter form the received firstsignal. Operation proceeds from step 1212 to step 1214 in which thewireless terminal receives another signal from the first communicationsdevice, and then in step 1216 the wireless terminal derives a secondparameter from another signal received from said first communicationsdevice. Operation proceeds from step 1216 to step 1218.

In step 1218, the wireless terminal determines at least one transmitfrequency to be used for transmitting said second signal from thederived frequency information. Operations proceed from step 1218 viaconnecting node A 1220 to step 1222 of FIG 12B.

In step 1222, the wireless terminal generates a second signal as afunction of one of device identifier corresponding to said wirelessterminal and a user identifier corresponding to a user of said wirelessterminal. Then, in step 1224, the wireless communications devicetransmits said second signal to said another communications deviceduring said first time interval. Step 1224 includes sub-step 1225 inwhich the wireless terminal transmits said second signal into saidsecond communications band, which is different from said firstcommunications band. Operation proceeds from step 1224 to step 1226.

In step 1226, the wireless terminal determines at least one additionaltransit time as a function of said parameter derived from said firstsignal. Step 1226 includes sub-step 1227, in which the wireless terminaluses a time hopping function which uses said parameter and/or saidsecond parameter as input parameters. Operation proceeds from step 1226to step 1228.

In step 1228, the wireless terminal establishes a peer to peercommunications session with said another device using timingsynchronization information derived from said first signal. Then, instep 1230, the wireless terminal exchanges user data as part of saidpeer to peer communications session, said user data including at leastone of voice data, other audio data, image data, text data and filedata, said peer to peer communications session being conducted directlybetween said wireless terminal and said another device over a directairlink.

In some embodiments the first and second communications bands arenon-overlapping. In various embodiments, the first and secondcommunications bands are partially overlapping. In some embodiments, thesecond signal includes a beacon signal burst, e.g., an OFDM beaconsignal burst including at least one beacon symbol. In some embodiments,the second signal is a pseudo noise sequence signal transmitted over thefrequency spectrum of the second frequency band. In some embodimentsboth the first and second signals are OFDM signals. In some,embodiments, both the first and second signals are CDMA signals. In someembodiments, both the first and second signals are GSM signals. In someembodiments the first signal is a GSM signal and the second signal is anOFDM signal. In some embodiments, the first signal is a CDMA signal andthe second signal is an OFDM signal. In various embodiments the firstsignal is a satellite broadcast signal, e.g., a GPS signal, a timingreference signal, a reference signal obtained from a geostationarysatellite, a signal from a satellite TV and/or radio broadcast, etc.,and the second signal is a terrestrial broadcast signal. The terrestrialbroadcast signal is e.g., from a fixed position base station, from afixed position special transmitter, e.g., a beacon transmitter, or froma movable transmitter temporarily stationed at a fixed site to provide areference such as a beacon signal, to be available for use by mobilenodes in the vicinity for a peer to peer network. In some embodiments,the first signal is received from a terrestrial cellular network and thewireless terminal is a mobile handset.

One exemplary embodiment will now be described corresponding toflowchart 1200 of FIG. 12. The wireless terminal is a first mobile node,and the another communications device is a second mobile node whichparticipates in a peer to peer communications session with the firstmobile node. The first communications device is a device such as a basestation, special beacon transmitter satellite, etc., which providesreference information to be used by the wireless terminal and anothercommunications device. The first signal is an OFDM beacon signal burstincluding at least one beacon symbol, e.g., a high energy tone,transmitted into the first frequency band. The another signal is, e.g.,a non-beacon broadcast signal transmitted from the first communicationsdevice. Reference timing information is derived from the first signaland used in determining a time for the wireless terminal to receivebeacon signals from other wireless terminals, e.g., peers, and indetermining a time to transmit its own user beacon signal. The secondsignal is an OFDM user beacon signal burst including at least one beaconsymbol, which is generated as a function of an identifier associatedwith the wireless terminal or wireless terminal user. From the receivedfirst signal the wireless terminal derives the second communicationsband, which is the communications band to be used for peer to peercommunications, which includes transmit frequencies of the user beaconto be generated by the wireless terminal. In this embodiment, the firstand second communications bands are non-overlapping. Thus the wirelessterminal's user beacon, and peer to peer user data are communicated intothe same band, the second communications band. First and secondparameters are input control parameters used in a time hopping sequenceassociated with user beacon signals generated and transmitted by thewireless terminal. For example, one of first and second parameters mayprovide an indication or notion of time and the other may provide anidentifier associated with the transmitter. The wireless terminal timehops the relative position of the beacon burst within a time window fromone beacon burst to the next, in accordance with the hopping sequenceusing the input control parameters.

FIG. 13 is a drawing of an exemplary wireless terminal 2300, e.g.,mobile node, implemented in accordance with various embodiments.Exemplary wireless terminal 2300 includes a receiver module 2302, atransmission module 2304, a coupling module 2303, a processor 2306, userI/O devices 2308, a power supply module 2310 and memory 2312 coupledtogether via a bus 2314 over which the various elements may interchangedata and information. Memory 2312 includes routines 2316 anddata/information 2318. The processor 2306, e.g., a CPU, executes theroutines and uses data/information 2318 in memory 2312 to control theoperation of the wireless terminal 2300 and implement methods.

Coupling module 2303, e.g., a duplex module, couples the receiver module2302 to antenna 2305 and the transmission module 2304 to antenna 2305.Power supply module 2312, which includes a battery 2311, is used topower up the various components of the wireless terminal. Power isdistributed from the power supply module 2310 to the various components(2302, 2303, 2304, 2306, 2308, 2312), via a power bus 2309. User I/Odevices 2308 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc. User I/O devices 2308 are used foroperations including inputting user data, accessing output user data,and controlling at least some functions and operations of the wirelessterminal, e.g., initiating a peer to peer communications session.

Routines 2316 include a transmission interval timing determinationmodule 2320, a receive interval timing determination module 2322, atransmission band control module 2324, a peer to peer communicationsband determination module 2326, a second signal generation module 2328,an additional transmit time determination module 2330, a peer to peercommunications establishment module 2332, a peer to peer sessionmanagement module 2334, a frequency information recovery module 2336,and a transmission frequency determination module 2338. Data/information2318 includes a received 1^(st) signal 2340, a determined first timeinterval 2342, 1^(st) frequency band information 2358, a second signal2344, a determined 2^(nd) time interval 2346, 2^(nd) frequency bandinformation 2360, device identification information 2362, useridentification information 2364, time hopping function information 2348,a first time hopping function input parameter 2350, a second timehopping function input parameter 2352, a plurality of transmit timescorresponding to beacon burst transmissions (transmit time for beaconburst 1 2354, . . . , transmit time for beacon burst n 2356), conveyedfrequency information 2366, and peer to peer session information 2368.The peer to peer session information 2368 includes peer identificationinformation 2370, received user data 2372, user data to be transmitted2374, and transmit frequency information 2376.

Receiver module 2302, e.g., a receiver, receives a first signal from afirst communication band, said first signal being from a firstcommunications device which broadcasts on a recurring basis. The firstcommunications device is a different communications device than thecommunications device with which wireless terminal 2300 has acommunications session. Information representing the received 1^(st)signal 2340 is stored in memory 2312, and 1^(st) frequency bandinformation 2358 identifies the frequency band to which the receivermodule is tuned when receiving the 1^(st) signal. The 1^(st) signal ise.g., a broadcast signal used to obtain a timing reference by thewireless terminal 2300. Receiver module 2302 also receives signals fromother communication devices, e.g., a part of communications sessionssuch as peer to peer communications sessions. Some of the receivedsignals include user data 2372. In some embodiments, receiver module2302 supports a plurality of signaling technologies e.g., the firstsignal which is used as a reference may be and sometimes is a differenttechnology than the technology used for peer to peer communicationssessions.

Transmission module 2304 e.g., an OFDM transmitter is used fortransmitting a second signal 23 to a communications device, e.g., a peerwireless terminal, during a determined 1^(st) time interval 2342. Insome embodiments, the second signal 2344 includes a beacon signal burst,e.g., an OFDM beacon signal burst including at least one beacon symbol.Transmission module 2304 also transmits user data 2344, as part of apeer to peer communications session using transmit frequency information2376.

Transmission interval timing, determination module 2322 determines,based on the received 1^(st) signal 2340, a first time interval 2342 tobe used for transmitting 2^(nd) signal 2344, e.g., a WT 2300 beaconsignal burst to another communications device, e.g., a peer wirelessterminal. Receive interval timing determination module 2322 determines,based on the received 1^(st) signal 2340, a 2^(nd) time interval 2346 tobe used for receiving signals from devices other than the device whichtransmitted the 1^(st) signal. In some embodiments, the 2^(nd) timeinterval is a time interval in which wireless terminal 2300 is toreceive and monitor for beacon signals from another communicationsdevice, e.g., peer wireless terminal.

Transmission band control module 2324 controls the wireless terminal2300 to transmit the 2^(nd) signal 2344, e.g., WTs 2300's beacon signalburst, in a second communications band identified by 2^(nd) frequencyband information 2360. In some embodiments, the 2^(nd) frequency band isdifferent from the 1^(st) frequency band. For example, the wirelessterminal 2300 receives a broadcast signal used for timingsynchronization, in a 1^(st) band and transmits its user beacon in a2^(nd) frequency band, which is a different band.

Peer to peer communications band determination module 2326 determines,prior to transmitting the 2^(nd) signal 2344 the 2^(nd) communicationband based on the 1^(st) received communications signal 2340. Thus peerto peer communications band determination module 2326 determines 2^(nd)frequency band information 2360. In some embodiments, the 1^(st) and2^(nd) frequency bands are non-overlapping frequency bands. In someembodiments, the 1^(st) and 2^(nd) frequency bands partially overlappingfrequency bands.

Second signal generation module 2328, generates 2^(nd) signal 2344,prior to transmitting the second signal as a function of one of a deviceidentifier 2362 corresponding to the wireless terminal and a useridentifier 2364 corresponding to a user of wireless terminal 2300. Insome embodiments, second signal generation module 2328 generatessignaling including beacon signal bursts, e.g., OFDM beacon signalbursts including at least one beacon symbol. In some embodiments, thesecond signal is a pseudo noise sequence transmitted over the secondfrequency band.

Additional transmit time determination module 2330 determines at leastone additional transmit time as a function of a parameter derived fromthe 1^(st) signal, e.g., time hopping function input parameter 1 2350.The additional transmit time determination module 2330 uses a timehopping function which uses parameter 2350 as an input. Time hoppingfunction information 2348 includes, e.g. information defining the timehopping sequence. In some embodiments the time hopping function uses asecond input parameter 2352 derived from another signal received fromthe communications device which transmitted the 1^(st) broadcast signal.For example the another signal may be, and sometimes is, a non-beaconbroadcast signal communicating the 2^(nd) input parameter. The anothersignal nay be, and sometimes is, another beacon signal burst.

Peer to peer communications establishment module 2332 is used toestablish a peer to peer communication session with another device,e.g., a peer node, using timing synchronization information derived fromthe received 1^(st) signal 2340.

Peer to peer session management module 2334 controls the exchange ofused data including at least one of voice data, text data, and imagedata, said peer to peer communications session being conducted directlybetween the wireless terminal and another device, e.g., peer wirelessterminal, over a direct air link.

Frequency information recovery module 2336 recovers conveyed frequencyinformation 2366 from the received 1^(st) signal 2340, prior totransmitting the second signal 2344, deriving frequency information fromthe received 1^(st) signal 2340. For example, the 1^(st) signal conveyedinformation identifying the 2^(nd) frequency band, the 2^(nd) frequencyband to be used by wireless terminal 2300 for transmitting its userbeacon signal and for peer to peer user data communications.

Transmission frequency determination module 2338 determines at least onetransmit frequency to be used for transmitting the second signal fromderived frequency information. Information including in 2376 is anoutput of module 2338. Transmit information 2376 includes, e.g.,frequency band information and/or individual tone identificationinformation. In some embodiments, transmit frequency informationidentifies OFDM tones used to convey beacon symbols of beacon signalbursts to be transmitted by wireless terminal 2300. In some suchembodiments, beacon symbol tones are tone hopped from one burst toanother in a sequence of bursts in accordance with a tone hoppingsequence.

In some embodiments, both the first and second signals are OFDM signals.In some embodiments, the first signal is a GSM signal and the secondsignal is an OFDM signal. In some embodiments, the first signal is aCDMA signal and the second signal is an OFDM signal. In someembodiments, the first signal is a satellite broadcast signal and thesecond signal is a terrestrial broadcast signal. In some embodiments,the first signal is received from a terrestrial cellular network and thewireless terminal is a mobile handset.

FIG. 14 is a drawing of a flowchart 1300 of an exemplary method ofoperating a wireless terminal which supports both peer to peercommunications and communications with a base station in accordance withvarious embodiments. Operation starts in step 1302, where the wirelessterminal is powered on and initialized and proceeds to step 1304. Instep 1304, the wireless terminal receives a first signal from a firstcommunications band, the first signal being from a base station.Operation proceeds from step 1304 to step 1306. In step 1306, thewireless terminal determines the frequency of a second communicationsband from the first signal, and in step 1308, the wireless terminaldetermines an interval of time during which the wireless terminal is tomonitor for a second signal in the second communication band, thedetermination of the time interval being based on informationcommunicated by the first signal, e.g., a time reference communicated.Operation proceeds from step 1308 to step 1310.

In step 1310, the wireless terminal determines from said first signallink the quality of a first link between said base station and saidwireless terminal, and in step 1312, the wireless terminal predicts afirst data throughput to the base station based on the first determinedlink quality. Step 1312 includes sub-step 1314, in which the wirelessterminal uses maximum transmission power information in the first linkquality determination. The maximum transmission power informationincludes, e.g., at least one of a government restriction on maximumtransmission power and device output capability. Operation proceeds fromstep 1312 to step 1316.

In step 1316, the wireless terminal monitors during said determined timeinterval to receive said second signal, and then in step 1318, thewireless terminal receives said second signal from the secondcommunications band, said second communications band being differentfrom the first communications band, said second signal being from a peerwireless terminal. In some embodiments, the first and second signal eachinclude at least one beacon signal burst.

Operation proceeds from step 1318 to step 1320. In step 1320, thewireless terminal predicts a second data throughput to the peer wirelessterminal based on the second determined link quality. Step 1320 includessub-step 1322 in which the wireless terminal uses maximum transmissionpower information in the second link quality determination. The maximumtransmission power information includes, e.g., at least one of agovernment restriction on maximum transmission power and device outputcapability. Operation proceeds from step 1320 to step 1324, in which thewireless terminal selects between said first and second links for acommunications session based on the determined quality of the first andsecond links. Step 1324 includes alternative sub-steps 1326, l328, and1330.

In alternative sub-step 1326, the wireless terminal selects the one ofthe first and second links having a higher data throughput. Inalternative sub-step 1328, the wireless terminal performs the selectionas a function of energy required to maintain said first and secondlinks, said selecting including selecting the one of the first andsecond links satisfying a link quality requirement and also requiringthe least amount of energy to maintain. In alternative sub-step 1330,the wireless terminal performs selection as a function of a lest costrouting determination that takes into consideration and economic costassociated with using individual ones of said first and second links.

FIG. 15 is a drawing of an exemplary wireless terminal 2400, e.g.,mobile node, implemented in accordance with various embodiments.Exemplary wireless terminal 2400 supports both peer to peercommunications and communications via a base station. Exemplary wirelessterminal 2400 includes a receiver module 2402, a transmitter module2404, a processor 2406, user I/O devices 2408, a memory 2410 coupledtogether via a bus 2412 over which the various elements may exchangedata and information. Memory 2410 includes routines 2414 anddata/information 2416. The processor 2406, e.g., a CPU, executes theroutines 2414 and uses the data/information 2416 in memory 2410 tocontrol the operation of the wireless terminal 2400 and implementmethods.

Receiver module 2402, e.g., an OFDM receiver, is coupled to receiveantenna 2403 via which the wireless terminal 2400 receives signals frombase stations and other wireless terminals. Transmitter module 2404,e.g., an OFDM transmitter, is coupled to transmit antenna 2405 via whichthe wireless terminal 2400 transmits signals to base stations and toother wireless terminals. In some embodiments, the same antenna is usedfor both the receiver and transmitter modules (2402, 2404).

User I/O devices 2408 include, e.g., keypad, keyboard, switches, mouse,microphone speaker, display, etc. User I/O devices 2408 are used foroperations including inputting user data, accessing output user data,and controlling at least some functions and operations of the wirelessterminal, e.g., initiating a communications session.

Routines 2414 include a communications routine 2418 and wirelessterminal control routines 2420. The communications routine 2418implements the various communications protocols used by the wirelessterminal 2400. The wireless terminal control routines 2420 include abase station link quality determination module 2422, a peer to peer linkquality determination module 2424, a link selection module 2426, abeacon burst processing module 2428, a user data recovery module 2430, afirst data throughput determination module 2432, a second datathroughput determination module 2434, a power requirement estimationmodule 2436, a routing cost determination module 2438, a frequency banddetermination module 2440, a monitor interval determination module 2442,and a peer to peer signal monitoring module 2444.

Data/information 2416 includes a received 1^(st) signal 2446, 1^(st)frequency band information 2448, base station identification informationcorresponding to the base station which transmitted the 1^(st) signal2450, recovered 1^(st) link information 2452, predicted 1^(st) link datathroughput 2454, estimated amount of energy required to maintain 1^(st)link 2456, routing cost determination associated with 1^(st) link 2458,determined 1^(st) link quality 2460, received 2^(nd) signal 2462, 2^(nd)frequency band information 2464, peer wireless terminal identificationinformation corresponding to the peer wireless terminal whichtransmitted the 2^(nd) signal 2465, recovered 2^(nd) link information2466, predicated 2nd link data throughput 2468, estimated amount ofenergy required to maintain 2^(nd) link 2470, routing cost determinationassociated with 2^(nd) link 2472, determined 2^(nd) link quality 2474,selected link information 2476, recovered user data 2478, stored maximumtransmission power information 2480, stored link, quality requirementinformation 2486, and determined interval of time to monitor for secondsignals 2488. Stored maximum transmission power information 2480includes government restriction information 2482 and device outputcapability information 2484

Receiver module 2402 receives a 1^(st) signal from a 1^(st)communication band, the first signal being from a base station. Received1^(st) signal 2446 includes information representing the 1^(st) signalwhich was received in the band identified by 1^(st) frequency bandinformation 2448 and was transmitted by the base station identified ininformation 2450. Receiver module 2402 also receives a second signalfrom a second communications band which is different from the firstcommunications band, said second signal being from a peer wirelessterminal. Received 2^(nd) signal 2462 includes information representingthe 2^(nd) signal which was received in the band identified by 2^(nd)frequency band information 2464 and was transmitted by the peer wirelessterminal identified in information 2465. In some embodiments, the firstand second signals each include at least one beacon signal burst, e.g.,an OFDM beacon signal burst including at least one beacon symbol.

Base station link quality determination module 2422 determines, from thefirst signal, link quality of a first link between a base station whichtransmitted the first signal and the wireless terminal 2400, anddetermined 1^(st) link quality 2460 is an output of module 2422. Peer topeer link quality determination module 2424 determines, from the secondsignal, link quality of a second link between a peer wireless terminalwhich transmitted the second signal and the wireless terminal 2400, anddetermined 2^(nd) link quality 2474 is an output of module 2424.

Link selection module 2426 selects between 1^(st) and 2^(nd) links, fora communications session, based on the determined quality of the firstand second links. Determined 1^(st) link quality 2460 and determined2^(nd) link quality 2474 are inputs to link selection module 2426 andselected link information 2476 is an output of link selection module2426 which identifies the selected link.

Beacon burst processing module 2428 recovers link information frombeacon signal bursts (recovered 1^(st) link information 2452corresponding to 1^(st) signal, recovered 2^(nd) link information 2466corresponding to 2^(nd) signal). User data recovery module 2430 recoversuser data 2478 from non-beacon signals used to communication user dataas part of a communications session. At some times the recovered userdata 2478 is from a peer to peer communication session, while at othertimes the recovered user data is from a communications session in whichthe user data is relayed through a base station serving as an accessnode.

First data throughput determination module 2432 predicts a first datathroughput 2454 to the base station based on the first determined linkquality 2460. Second data throughput determination nodule 2434 predictsa second data throughput 2468 to the peer wireless terminal based on thesecond determined link quality 2474. Link selection module 2426 includesa throughput based selection module for selecting the one of the firstand second links having the higher data throughput. First datathroughput determination module 2432 uses the stored maximumtransmission power information 2480 in predicting the first datathroughput 2454. Second data throughput determination module 2434 usesthe stored maximum transmission power information 2480 in predicting thesecond data throughput 2468.

Power requirement estimation module 2436 estimates the amount of energyrequired to maintain the 1^(st) and 2^(nd) links (estimated amount ofenergy required to maintain 1^(st) link 2456, estimated amount of energyrequired to maintain 2^(nd) link 2470). Link section module 2426 alsoperforms selection between first and second links for a communicationssession as a function of energy required to maintain first and secondlinks, said selecting including selecting the one of the 1^(st) and 2ndlinks satisfying a link quality requirement 2486 and also requiring theleast amount of energy to maintain.

Routing cost determination module 2438 performs a routing costdetermination that takes into consideration economic costs associatedwith using individual ones of the first and second links. Routing costdetermination associated with 1^(st) link 2458 and routing costdetermination associated with 2^(nd) link 2472 are outputs of module2438. Link selection module 2426 also performs selection between firstand second links as a function of least cost routing determination,e.g., using info (2458, 2472) that takes into consideration economiccosts associated with individual ones of the first and second links.

Frequency band determination module 2440 determines, prior to receivingthe second signal, the frequency band of the second signal from thefirst signal. Thus a base station identifies the frequency band to beused for peer to peer communications in its vicinity. Monitor intervaldetermination module 2442 determines an interval of time during whichsaid wireless terminal 2400 is to monitor for second signals 2488, e.g.,a time interval for wireless terminal 2400 to search for user beaconsignals from peer nodes. Peer to peer signal monitoring module 2444monitors for a signal from a peer wireless terminal during the intervalidentified to receive second signals, e.g., peer to peer signalmonitoring module 2444 monitors for user beacon signal bursts from peernodes.

In some embodiments, the selection module 2426 changes selectioncriteria and/or re-weights selection criteria as a function of basestation identification information, peer identification information,priority information, type of information anticipated to becommunicated, wireless terminal 2400 current conditions, and/or latencyrequirements. For example, selection module 2426, in some embodiments,heavily weights the selection as a function of energy requirements, whena low battery power condition is detected in wireless terminal 2400. Asanother example, selection module 2426 heavily weights the selectionbased on predicted data throughput when a large amount of time criticaldata is anticipated to be communicated.

FIG. 16 is a drawing of a flowchart 1400 of an exemplary method ofoperating, a base station in accordance with various embodiments.Operation starts in step 1402, where the base station is powered on andinitialized and proceeds to step 1404. In step 1404, the base stationtransmits a beacon signal, said beacon signal including at least onebeacon signal burst, said beacon signal conveying information about apeer to peer frequency band, e.g., a peer to peer frequency band whichis available for use in the vicinity of the base station. Step 1404includes sub-step 1406. In sub-step 1406, the base station transmits thebeacon signal into a first communications band, said beacon signalconveyed information indicating a second frequency band which is used assaid peer to peer frequency band, said second frequency band beingdifferent from said first frequency band. Operation proceeds from step1404 to step 1408.

In step 1408, the base station transmits a second beacon signal into thefirst communications band, said second beacon signal providing timingsynchronization information to a plurality of wireless terminals usingthe base station as an access node. Operation proceeds from step 1408 tostep 1410.

In step 1410, the base station receives data from at least some of saidplurality of wireless terminals using said base station as an accessnode for communication through said access node, and in step 1412, thebase station transmits user data to at least some of said plurality ofwireless terminals using said base station as an access node using thefirst frequency band. Operation proceeds from step 1412 to step 1404.

In some embodiments, the first frequency band is used in a time divisionmultiplexed manner, and said step of receiving data (1410) receives datain the first communication band during a first time period and said stepof transmitting user data into the first frequency band (1412) isperformed during a second time period which is different from said firsttime period. In some other embodiments, the base station uses the firstfrequency band for transmitting signals including said beacon signal,said second beacon signal and said user data signals, while a thirdcommunications band is used for receiving user data signals fromwireless terminals using the base station as an access point. In somesuch embodiments, the first, second and third communications bands aredifferent and non-overlapping. In some such embodiments, the basestation transmits and receives user data concurrently.

In some embodiments, the average base station transmitted power into thesecond communications band over a 1 minute time period is less than1/1000 the average base station transmitted power into the firstfrequency band over the same 1 minute interval. In some suchembodiments, the base station does not transmit any power into thesecond frequency band.

In another embodiment, which is a variation of embodiments describedwith respect to flowchart 1400, the base station transmits its accessnode beacon signal and user data into the first frequency band, andtransmits a beacon signal for peer to peer communications into thesecond frequency band, the second frequency band being used for peer topeer communications, but the base station does not transmit any userdata into the second frequency band. In some such embodiments, theaverage base station transmitted power into the second communicationsband over a 1 minute time period is less than 1/1000 the average basestation transmitted power into the first frequency band over the same 1minute interval.

In still another embodiment, which is a variation with respect toflowchart 1400, the base station transmits both its access node beaconsignal and its peer to peer node beacon signal in a first frequency bandused for beacon signals. In addition, the base station transmits userdata intended for wireless terminals using the base station as an accessnode into a second frequency band; and the base station refrains fromtransmitting user data into a third frequency band which is utilized forpeer to peer communications, wherein said first, second and thirdcommunications bands are non-overlapping.

FIG. 17 is a drawing of an exemplary base station 2500 in accordancewith various embodiments. Exemplary base station 9500 includes areceiver module 2502, with associated antenna 2501, a transmissionmodule 2504, with associated transmitter antenna 2503, a processor 2506,and I/O interface 2508, and memory 2510 coupled together via a bus 2512over which the various elements interchange data and information. Memoryincludes routines 2514 and data/information 2516. The processor 2506,e.g., a CPU, executes the routines 2514 and uses the data/information2516 in memory 2510 to control the operation of the base station 2500and implement methods, e.g., the method of FIG. 16.

Routines 2514 include a beacon signal generation module 2518, afrequency band control module 2520, a user data transmission controlmodule 2522, a transmission power control module 2524, and an accessnode beacon signal generation module 2526. Data/information 2516includes stored peer to peer beacon signal characteristic information2528, stored access node beacon signal characteristic information 2534,peer to peer beacon signal transmission band information 2556, accessnode beacon signal transmission band information 2558, peer to peercommunications band information 2560, base station access node bandinformation 2562, timing information 2564, transmission powerinformation 2566, and wireless terminal data/information 2540corresponding to wireless terminals using the base station 2500 as anaccess node.

Stored peer to peer beacon signal characteristic information 2528includes one or more sets of beacon burst information (beacon burst 1information 2530, . . . , beacon burst N information 2532). Storedaccess node beacon signal characteristic information 2534 includes oneor more sets of beacon burst information (beacon burst 1 information2536, . . . , beacon burst N information 2538).

WTs data/information 2540 corresponding to WTs using the base station asan access node includes a plurality of sets of information (WT 1data/information 2542, . . . , WT n data/information 2544). WT 1data/information 2542 includes received user data 2546, user data to betransmitted 2548, a base station assigned wireless terminal identifier2550, state information 2552, and communications session information2554.

Receiver module 2502, e.g., an OFDM receiver, receives uplink signalsfrom wireless terminals using the base station 2500 as an access node.The received signals include user data signals, e.g., traffic channelsignals, from a plurality of wireless terminals using base station 2500as an access node for communication through the access node. Receiveduser data 2546 corresponding to WT 1 represents user data obtained fromreceived signals from one exemplary wireless terminal using base station2500 as an access node.

Transmitter module 2504, e.g., an OFDM transmitter, transmits signals towireless terminals in its vicinity. The transmitted signals include agenerated beacon signal intended to support peer to peer communicationsin its vicinity. The generated beacon signal includes at least onebeacon signal burst and conveys information about a peer to peerfrequency band. The transmitted signals also include a generated secondbeacon signal intended to support access node operations, the generatedsecond beacon signal providing timing synchronization information to aplurality of wireless terminals using the base station as an accessnode. In some embodiments, the generated beacon signal conveying peer topeer frequency band information and the generated second beacon signalcommunicating access node timing synchronization information aretransmitted into the same frequency band. The transmitter 2504 alsotransmits control data and user data to wireless terminals using thebase station as an attachment point. User data to be transmitted 2548,corresponding to wireless terminal 1, is an example of user data that istransmitted by the base station 2500, e.g., in downlink traffic channelsegments, to a wireless terminal using the base station as an accessnode. User data includes, e.g., voice, image, text, and/or file data.

In some embodiments, receiving data includes receiving data fromwireless terminals using the base station as an access node in a firstfrequency band during a first period of time and transmitting user datainto the first frequency band is performed during a second period oftime which is different from the first period of time, said frequencyband being used in a time division multiplexed manner. Timinginformation 2564, in some embodiments, identifies first and secondperiods of time. In various embodiments, the base station does nottransmit or receive user data into a second frequency band designated tobe used for peer to peer communications.

I/O interface 2508 couples the base station 2500 to other network nodes,e.g., other base station, AAA node, home agent nodes, etc. and/or theInternet. I/O interface 2508, by coupling base station 2500 to abackhaul network allows a wireless terminal using base station 2500 asits point of network attachment to participate in a communicationssession with another wireless terminal using a different base station asits point of network attachment.

Beacon signal generation module 2518 generates a beacon signal, saidbeacon signal including at least one beacon signal burst, said beaconsignal burst conveying information about a peer to peer frequency band,e.g., identifying the peer to peer frequency band. Stored peer to peerbeacon signal characteristic information 2528 is used by beacon signalgeneration module 2518 in generating the beacon signal. In someembodiment, the generated beacon signal by module 2518 conveys peer topeer communications band information 2560,

Frequency band control module 2520 controls transmission of the beaconsignal generated by module 2518 into a first communications band, thebeacon signal conveying information indicating a second frequency bandwhich is used as the peer to peer frequency band, said second frequencyband being different from the first frequency band. In some suchembodiments, the first frequency band is the frequency band identifiedby peer to peer beacon signal transmission band information 2556 and thesecond frequency band is the frequency band identified by peer to peercommunication band information 2560.

User data transmission control module 2522 controls transmission of userdata to multiple ones of the plurality of wireless terminals using thebase station as an access point using a transmission band identified bythe base station access node information. In some embodiments, the bandused for transmission of user data to a wireless terminal using the basestation as a point of network attachment is the same as the first bandwhich is the band into which the generated beacon signal for peer topeer communications is transmitted.

Transmission power control module 2524 controls transmission power intothe second frequency band, which is the frequency band used for peer topeer communications, to keep the base station average transmitted powerinto the second frequency band over a 1 minute time period less than1/1000 the average transmitted power transmitted into the firstfrequency band, e.g., the frequency band used for the beacon signal andaccess node related downlink signaling including user data. In someembodiments, the base station 2500 does not transmit into the secondfrequency band, which is used for peer to peer communications.

Access node beacon signal generation module 2526 uses thedata/information 2516 including the access node beacon signalcharacteristic information 2534 to generate a second beacon signal, thesecond beacon signal providing, timing synchronization information tothe plurality of wireless terminals using the base station 2500 as anaccess node.

In some embodiments, (i) the band into which the beacon signalidentifying the peer to peer band is transmitted, (ii) the band intowhich the beacon signal used for wireless terminal timingsynchronization with regard to access node operations is transmitted,and (iii) the band used for dowlink access node signaling to wirelessterminals is the same band. In some such embodiments, the band used forpeer to peer communications is a different non-overlapping band. Thusinformation 2556, 2558, and 2562, in some embodiments, identify the sameband, while information 2560 identifies a different band.

FIG. 18 is a drawing of an exemplary beacon signal transmissionapparatus 1500 in accordance with various embodiments. Exemplary beaconsignal transmission apparatus 1500 is a free standing device and doesnot include any transmitter used to transmit user data to an individualuser device. Exemplary beacon signal transmission apparatus 1500includes a receiver module 1502, a beacon signal transmitter 1504, aprocessor 1506, a solar power supply module 1508, a power supply module1510, a memory 1512 coupled together via a bus 1514 over which thevarious elements may interchange data and information. The variouselements (1502, 1504, 1506, 1408, 1510, 1512) are coupled to a powersupply by bus 1507. Memory 1512 includes routines 1516 anddata/information 1518. The processor 1506, e.g., a CPU, executes theroutines 1516 and uses the data/information 1518 in memory 1512 tocontrol the apparatus 1500 and implement methods.

Routines 1516 include a beacon signal transmission control module 1520,a beacon signal generation module 1522, a receiver control module 1524and a received broadcast signal information recovery module 1526.Data/information 1518 includes stored beacon signal characteristicinformation 1528, stored beacon signal control information 1530,received broadcast signal information 1532, and beacon transmitteridentification information 1534. Stored beacon signal characteristicinformation 1528 includes one or more sets of beacon burst information(beacon burst 1 information 1536, . . . , beacon burst N information1538), beacon symbol information 1540, and power information 1542.Beacon burst 1 information 1536 includes information identifying beacontransmission units carrying a beacon symbol 1544 and beacon burstdurations information 1546. Stored beacon signal control information1530 includes beacon burst/frequency band/timing relationshipinformation 1548 and beacon burst/sector/timing relationship information1550. Received broadcast signal information 1532 includes timinginformation 1552.

Receiver module 1502 is coupled to receive antenna 1501 via which theapparatus 1500 receives signals, e.g., a signal used for timingsynchronization purposes. In some embodiments, the receiver is one of aGPS, GSM and CDMA receiver. In some embodiments, the receiver is an OFDMreceiver. In some embodiments, the receiver module 1502 includes thecapability to receive a plurality of different types of signals and,e.g., depending upon the area of deployment a different type of signalis received and utilized as a reference source. In some suchembodiments, the receiver control module 1524 follows a predeterminedordered sequence when determining reference signal search protocol.

Receiver 1502, under the control of receiver control module 1524,receives a broadcast signal and received broadcast signal informationrecovery module 1526 recovers received broadcast signal information 1532from the received broadcast signal including timing information 1552,e.g., a timing reference.

Beacon signal transmitter 1504, e.g., an OFDM transmitter, is coupled totransmit antennas (sector 1 antenna 1503, . . . , sector N antenna 1505)via which the apparatus 1500 transmits beacon signal bursts which areused to support a peer-peer communications network. Beacon signaltransmitter 1504 transmits a sequence of beacon signal bursts, eachbeacon signal burst including at least one beacon symbol. Beacon signaltransmission control module 1520 uses the data/information 1518 inmemory 1512 including stored beacon signal control information 1530 andtiming information 1552 to control the transmission of beacon burstsignals, e.g., controlling beacon signal burst transmission timing as afunction of the received broadcast signal which was detected andprocessed. Beacon signal transmission control module 1520 uses thedata/information 1518 including timing information 1552 and beaconburst/frequency band/timing relationship information 1548 to control thebeacon transmitter 1504 to transmit beacon signal bursts into differentfrequency bands at different times. Beacon signal transmission controlmodule 1520 uses the data/information 1518 including timing information1552 and beacon burst/sector/timing relationship information 1548 tocontrol the beacon transmitter 1504 to transmit beacon signal burstsinto sectors at different times. In some such embodiments, the beaconsignal transmission control module 1520 controls the beacon signaltransmitter 1504 to transmit into it most one sector at a time.

Solar power supply module 1508 includes solar cell 1509 for convertingsolar energy to electrical energy such that apparatus 1500 can be, andsometimes is solar powered. Power supply module 1510 includes battery1511 for storing energy such that apparatus can be, and sometimes ispowered by battery 1511. Some embodiments include a battery power supply1511, but do not include a solar power supply module 1508, e.g., withthe batteries being replaced and/or recharged periodically. In someembodiments, apparatus 1500 is expected to operate for the duration ofthe battery life and then be discarded or refitted with a replacementbattery. In some embodiments, the beacons signal transmission apparatus1500 is independently powered, e.g., operating from a portable gasoline,diesel, kerosene, propane, natural gas, and/or hydrogen based, generatorand/or fuel cell. Embodiments using solar, battery and/or otherindependent energy sources are advantageous in remote sites, where alocal power grid may be unavailable and/or in areas where a power gridis unreliable. In various embodiments, beacon signal transmission poweris coupled to a power grid for receiving power.

Beacon signal generation module 1522 uses the data/information includingstored beacons signal characteristic information 1528 and/or beacontransmitter identification information 1534 to generate a sequence ofbeacon signal bursts, each beacon signal bust including at least onebeacon symbol, the beacon signal burst intended to be used to supportpeer to peer communications. Information identifying beacon transmissionunits carrying a beacon symbol 1544 include, e.g., informationidentifying a subset of OFDM tone-symbols designated to carry a highpower beacon symbol in a set of OFDM tone-symbols of beacon burst 1.Beacon burst symbol information 1540 includes information defining abeacon symbol, e.g., a modulation symbol value, while power information1542 includes transmission power level information associated with thebeacon signal. In some embodiments, each of the beacon symbols iscontrolled to be transmitted at the same transmission power level. Insome embodiments, each of the beacon symbols corresponding too a givensector and a given frequency band are controlled to be transmitted atthe same transmission power level, with at least some beacon symbolscorresponding to different sectors and/or frequency bands aretransmitted at different power levels.

FIG. 19 is a drawing of a flowchart 2600 of an exemplary method ofoperating a beacon signal transmitter device in accordance with variousembodiments. The beacon signal transmitter device is, e.g., a freestanding device, and the beacon signal transmitter device does notinclude any transmitter used to transmit user data to an individual userdevice, e.g., wireless terminal. In various embodiments, the beaconsignal transmitter device includes an OFDM beacon signal transmitter fortransmitting OFDM beacon signal burst, each beacon signal burstincluding at least one relatively high power OFDM beacon symbol, e.g.,with respect to the transmission power levels of data symbolstransmitted by wireless terminals communicating in a peer to peercommunications session in the local region being serviced by the beaconsignal transmitter device.

Operation starts in step 2602, where the beacon signal transmitterdevice is powered on and initialized. Operation proceeds from start step2602 and proceeds to step 2604. In step 2604, the beacon signaltransmitter device scans for different types of broadcast signals thatcan be used as timing reference signals. In some embodiments, thescanning is performed based on a predetermined sequence based on atleast some geographic location information. Then, in step 2606, thebeacon signal transmitter device receives a broadcast signal, and instep 2608 determines a signal burst transmission timing, as a functionof the received broadcast signal. In some embodiments, the receiver is areceiver which includes at least one of a GPS receiver, a GSM receiver,and a CDMA receiver. Operation proceeds from step 2608 to step 2610.

In step 2610, the beacon signal transmitter device is operated totransmit a sequence of beacon signal bursts, each beacon signal burstincluding at least one beacon symbol. Step 2610 includes sub-steps 2612,2614, 2616, 2618, 2620, and 2622. In sub-step 2612, the beacon signaltransmitter device's transmitter is powered from one of: a battery powersource, a solar power source, and a power source which is independent ofa commercial power grid.

In sub-step 2614, the beacon signal transmitter device compares currenttiming information to predetermined schedule information. Operationproceeds from sub-step 2614 to sub-step 2616, in which the beacon signaltransmitter device determines if it is time to transmit a beacon signalburst or bursts. If it is determined in sub-step 2616, that it is nottime to transmit a beacon signal burst, then operation proceeds back tostep 2614 for additional comparison of timing information. However, ifit is determined in sub-step 2616, that the beacon signal transmitterdevice is scheduled to transmit a beacon signal burst(s), then operationproceeds to sub-step 2618, where the device determines the frequencyband or bands into which the beacon signal, burst(s) are to betransmitted. Operation proceeds from sub-step 2618 to sub-step 2620, inwhich the device determines the sector or sectors into which the beaconsignal burst or bursts are to be transmitted. Then, in sub-step 2622,the beacon signal transmitter device transmits the scheduled beaconsignal burst or bursts into the determined frequency band or bands intothe determined sector or sectors. Operation proceeds from sub-step 2622back to sub-step 2614 for additional time comparisons.

In various embodiments, the beacon signal transmitter device uses storedcontrol information to determine a plurality of frequency bands intowhich the beacon signal bursts are to be transmitted and the time atwhich the transmission of the beacon signal bursts are to occur. In someembodiments, the beacon signal transmitter device controls itstransmitter to transmit beacon signal burst into different frequencybands at different times. In some embodiments, the beacon signaltransmitter device controls its transmitter to use a multi-sectorantenna and to transmit beacon signal bursts into different sectors atdifferent times. In one such embodiment, the beacon signal transmitterdevice controls its transmitter to transmit into at most one sector at atime. In some embodiments, the beacon signal transmitter device controlsits transmitter to transmit into at most one frequency band at a time.

In various embodiments, the beacon signal transmitter controls itstransmitter to transmit into multiple frequency bands in each ofmultiple sectors of a cell. In some embodiments, the beacon signaltransmitter is controlled to transmit into at most one frequency band ofone sector at a given time at which beacon signal bursts aretransmitted.

In some embodiments, described with respect to flowchart 2600, thebeacon signal transmitter device obtains an external reference from areceived broadcast signal. In some embodiments, the beacon signaltransmitter does not include a receiver and does not receive a referencesignal. For example, the beacon signal transmitter device transmits itsbeacon signal bursts in accordance with stored schedule informationcorresponding to a recurring schedule, and the beacon signal transmitterdevice's timing is free running and not coordinated with any otherbeacon signal transmitter device.

FIG. 20 is a drawing of a flowchart 1600 of an exemplary method ofoperating a base station in accordance with various embodiments. Theexemplary base station switches between infrastructure spectrum use andpeer to spectrum use. Thus at different times spectrum e.g., a frequencyband, in the vicinity of the base station is used for differentpurposes. Operation starts in step 1602, where the base station ispowered on and initialized and proceeds to step 1604 and correctingnodes A 1606, B 1608, C 1610 and D 16l2.

In step 1604, the base station sets its mode to a second mode, e.g., anaccess mode operation mode with respect to a first frequency band. Inthis particular exemplary embodiment, the access mode with respect tothe first frequency band is the start-up default mode. In otherembodiments, the peer to peer mode of operation is the start-up defaultmode, and the base station starts up in a mode in which the firstfrequency band is designated to be used for peer to peer communications.Operation proceeds from step 1604 to steps 1614 and step 1616.

In step 1614, the base station transmits a second broadcast signalduring a second period of time conveying information that a firstfrequency band is be used as a non-peer to peer frequency band during asecond period of time. In step 1616, during the second period of time,the base station operates as a network access point to relay informationreceived over an airlink from a first communications device via acommunications network to a second communications device. Operationproceeds from step 1614 and step 1616 to step 1618.

Returning to connecting node A 1606, operation proceeds via connectingnode A 1606 to step 1628, where the base station monitors communicationsactivity level during the second mode of operation. Operation proceedsfrom step 1628 to step 1630, in which the base station checks whetherthe activity is below a predetermined threshold. If the level ofactivity is below a predetermined threshold, then operation proceeds tostep 1632, where the activity level information 1636 is updated toindicate a low level of activity e.g., corresponding to a level in whichthe mode is to be switched in response to the determined low level. Ifthe activity level is not below the threshold, then operation proceedsfrom step 1630 to step 634 in which the base station updates theactivity level information 1636 to indicate that the threshold is abovethe mode switch threshold, e.g., the base station should remain in thesecond mode based on the current level of activity. In some embodiments,the predetermined threshold corresponds to one wireless terminalcurrently using the base station as a network attachment point. In someembodiments, the predetermined threshold corresponds to one wirelessterminal currently, using the base station as a network attachment pointand communicating at least some user data via the base station fromand/or to that wireless terminal. Operation proceeds from step 1632 orstep 1634 to step 1628 for additional monitoring.

Returning to connecting node B 1608, operation proceeds via connectingnode B 1608 to step 1638, where the base station monitors for signalsfrom wireless terminals, while in a first mode of operation, indicatingthat a wireless terminal is seeking to use the base station as an accesspoint. Then, in step 1640, the base station checks if a signal wasdetected in step 1638. If a signal was detected operation proceeds fromstep 1640 to step 1642, where the base station updates the desiredactivity level information 1644. Operation proceeds from step 1642 tostep 1638 for additional monitoring. If a signal was not detected instep 1640 operation proceeds from step 1640 to step 1638 for additionalmonitoring.

Returning to connecting node C 1610, the operation proceeds viaconnecting node C 1610 to step 1646, where the base station monitors foran override, condition to occur. Step 1646 includes sub-step 1648 andsub-step 1650. In sub-step 1648, the base station monitors for receiptof a control signal indicating preemption of the first frequency band,e.g., by a government organization. In sub-step 1650, the base stationmonitors for receipt of a control signal indicating of preemption of thefirst frequency band, e.g., by a high priority user. Operation proceedsfrom step 1646 to step 1652.

In step 1652, the base station determines if a condition used tooverride the second mode of operation has occurred. If a condition hasoccurred, then operation proceeds from step 1652 to step 1654, where thebase station updates the mode override information 1656; otherwiseoperation proceeds from step 1652 to step 1646 for additionalmonitoring. Operation proceeds from step 1654 to step 1646 foradditional monitoring.

Returning to connecting node D 1612, operation proceeds via connectingnode D 1612 to step 1658, where the base station monitors for a modechange signal from a wireless terminal indicating that the wirelessterminal has the authority to alter the current mode of base stationoperation. In some embodiments, the information indicating that thewireless terminal has the authority to alter the current mode of basestation operation is one of a wireless terminal identifier, prioritylevel indicated and a wireless terminal user identifier. Operationproceeds from step 1658 to step 1660, in which the base stationdetermines whether such a mode change signal has occurred. If anauthorized mode change signal has been detected, operation proceeds fromstep 1660 to step 1662, where the base station updates the authorizedmode change information 1664; otherwise operation proceeds from step1660 to step 1658 for additional monitoring. Operation proceeds fromstep 1662 back to step 1658 for additional monitoring.

Returning to step 1618, in step 1618, the base station makes a modechange determination as a function of the activity level information1636, authorized mode change information 1664, and/or mode overrideinformation 1656. If the determination in step 1618, is that the modeshould change, then operation proceeds to step 1620, where the basestation switches from a second mode of operation to a first mode ofoperation in which the base station ceases to operate as an access node;otherwise operation proceeds from step 1618 to the input of steps 1614and 1616 and operation continues in the second node.

From step 1620, operation proceeds to step 1622, where the base stationtransmits a first broadcast signal during a first period of time, thefirst broadcast signal conveying information indicating that the firstfrequency band is to be used as a peer to peer frequency band. Operationproceeds from step 1622 to step 1624, where the base station determineswhether the mode should be changed. The base station uses the desiredactivity level information 1642 and/or authorized mode changeinformation 1664 in deciding whether to implement a mode change. If thedecision of step 1624 is that the mode should be changed, then operationproceeds to step 1626, where the base station switches from the firstmode of operation to the second mode of operation in which the basestation operates as an access node; otherwise operation proceeds fromstep 1624 to the input of step 1622, and the base station continues tooperate in the first mode, e.g., a mode supporting use of the firstfrequency band as a peer to peer band. Operation proceeds from step 1626to the inputs of steps 1614 and step 1616, where the base stationoperates in the second mode as an access node.

FIG. 21 is a drawing of an exemplary base station 2700 in accordancewith various embodiments. Exemplary base station 2700 includes thecapability to control reallocation of frequency spectrum betweeninfrastructure use, e.g., with the communications being directed throughthe base station 2700 functioning as an access node, and peer to peerspectrum use in which direct communications links between peer wirelessterminals are used.

Exemplary bas station 2700 includes a receiver module 2702, atransmission module 2704, a processor 2706, an I/O interface 2708, andmemory 2710 coupled together via a bus 2712 over which the variouselements may interchange data and information. Memory 2710 includesroutines 2714 and data/information 2716. The processor 2706, e.g., aCPU, executes the routines 2714 and uses the data/information 2716 inmemory 2710 to control the operation of the base station and implementmethods, e.g., the method of FIG. 20.

Receiver module 2702, e.g., an OFDM receiver, is coupled to receiveantenna 2701 via which the base station 2700 receives signals fromwireless terminal, e.g., when the base station is functioning as anaccess node. Transmission module 2704, e.g., an OFDM transmitter, iscoupled to transmit antenna 2703, via which the base station 2700transmits signals to wireless terminals. The transmitted signals,include broadcast signals such as beacon signals used to identifywhether a frequency spectrum is to be used in an access mode ofoperation or in a peer to peer communications session mode of operation.When the base station 2700 is using spectrum in an access mode ofoperation, the transmitter 2704 also transmits downlink signals, e.g.,pilot channel signals, control channel signals and user data signals,e.g., traffic channel signals to wireless terminals using the basestation 2700 as a point of network attachment.

Transmission module 2704 transmits a 1^(st) broadcast signal during a1^(st) period of time, the first broadcast signal conveying informationindicating that a first frequency band is to be used as a peer to peerfrequency band, and transmits a second broadcast signal during a secondperiod of time, the second broadcast signal conveying informationindicating that the first frequency band is to be used as a non-peer tofrequency band during the second period of time. In some embodiments,the 1^(st) and 2nd broadcast signals are beacon signals, e.g., OFDMbeacon signals. 1^(st) broadcast signal is generated by base station2700 based upon 1^(st) broadcast signal information 2730, e.g.,information identifying beacon symbols in beacon signal bursts andtiming beacon burst timing information representing the 1^(st) broadcastsignal, conveys peer to peer frequency band information. 2^(nd)broadcast signal is generated by base station 2700 based upon 2^(nd)broadcast signal information 2732, e.g., information identifying beaconsymbols in beacon signal bursts and timing beacon burst timinginformation representing the 2^(nd) broadcast signal, and conveysnon-peer to peer frequency band information 2744. Thus, a wirelessterminal can monitor for the presence of 1^(st) and 2^(nd) broadcastsignals from base station 2700 and, depending upon which one isdetected, determine how the first frequency band is currently, beingused.

I/O interface 2708 couples the base station 2700 to other network nodes,e.g., other base station, AAA node, home agent nodes, etc. and/or theInternet. I/O interface 2708, by coupling base station 2700 to abackhaul network allows a wireless terminal using base station 2700 asits point of network attachment to participate in a communicationssession with another wireless terminal using a different base station asits point of network attachment.

Routines 2714 include a transmitter control module 2718 a routing module2720, a mode control module 2722, a monitoring module 2724, a securitymodule 2726, and an activity level monitoring module 2728. The modecontrol module 2722 includes an override module 2723. Data/information2716 includes 1^(st) broadcast signal information 2730, 2^(nd) broadcastsignal information 2732, transmission timing information 2734, mode ofoperation information 2736, detected access request signal information2738, security information 2740, peer to peer frequency band information2742, non-peer to peer frequency band information 2744, network topologyinformation 2746, current network routing information 2748, determinedcurrent level of communications activity information 2750 and activitylevel based switching criteria 2756. The determined current level ofcommunications activity information 2750 includes a determined bandwidthutilization level 2752 and a determined number of active wirelessterminal users 2754. Activity level based switching criteria 2756includes a bandwidth utilization switching threshold 2758 and a numberof active terminals switching threshold 2760.

Transmitter control module 2718 controls the transmission module 2704 totransmit said first and second broadcast signals during said first andsecond periods of time, respectively, said first and second periods oftime being non-overlapping. Routing module 2720, which is used duringthe second period of time, routes user data received over an airlinkfrom a first communications device to a second communications device viaa communications network coupled to said base station. Routing module2720 uses network topology information 2746 and current network routinginformation 2748, e.g., information identifying congestion locations,failed nodes, alternative routing costs, delay considerationinformation, etc., to determined user data routing.

Mode control module switches between first and second modes ofoperation. The current mode of operation into which the base station hasbeen switched is indicated by mode of operation information 2736. Thefirst mode of operation corresponds to a node during the first periodsof time in which the first frequency band is being utilized as a peer topeer frequency band, while the second mode of operation is a mode ofoperation in which the first frequency band is being utilized for nonpeer to peer communications with the base station 2700 serving as anaccess node. When the mode control module 2722 switches from the secondmode of operation to the first mode of operation the mode control module2722 stops the base station 2700 from acting as an access node, e.g.,with regard to the first frequency band in the region into which the1^(st) broadcast signal transmission is directed.

Monitoring module 2724 monitors for and detects signals from wirelessterminals that are seeking to use the base station 2700 as an accessnode. For example, the base station 2700 may be currently in the firstmode of operation in which the first band is being used for peer to peercommunications; however, a wireless terminal may desire that the basestation reallocate the spectrum to access node operation, and send anaccess request signal to the base station which is detected andrecovered by monitoring module 2724. The recovered information is, e.g.,detected access request signal information. In some embodiments, thedetected access request signal information includes informationindicating that the wireless terminal making the request has theauthority to command the requested change. For example, the informationindicating that the wireless terminal has the authority to alter thecurrent mode of base station operation is in some embodimentscommunicated by one of a wireless terminal identifier, a priority levelindicated, and a wireless terminal user identifier. Security information2740 includes information utilized in making authorization evaluations,e.g., lists of authorized users, wireless terminal, and/or prioritylevel interpretation information. The base station 2700 considers therequest in making a decision as to whether or not to switch modes. Forexample, the base station switches from the first mode of operation tothe second mode of operation in response to a signal received from awireless terminal indicating that the wireless terminal is seeking touse the base station as an access node.

Security module 2726, using security information 2740, determines that asignal requesting a mode change is from a wireless terminal or userhaving the authority to command the requested mode change.

Activity level monitoring module 2728 determines the level ofcommunications activity 2750 while the base station is in the secondmode of operation functioning as an access node. The mode control module2722 is responsive to a low activity level, which it uses to initiate aswitch from the second mode of operation to the first mode of operation.In some embodiments, at some times, a low level of activity is indicatedby determined bandwidth utilization level 2752 being below apredetermined threshold, the bandwidth utilization switching threshold2758. In some embodiments, at some times, a low level of activity isindicated by determined number of active, wireless terminals 2754 beingbelow a predetermined threshold, the number of active terminalsswitching threshold 2760. In various embodiments, the determined numberof active wireless terminals 2754 indicates the number of wirelessterminals currently using the base station as an access point. In someembodiments, the number of active terminals switching threshold is setto 1.

Override module 2723 detects when a current mode override conditionoccurs. The current mode override condition is, e.g., the receipt of acontrol signal indicating preemption of the first frequency band. Thepreemption can be, and sometimes is, by a government organization.Alternatively, the preemption can be, and sometimes is, by a highpriority user. The control signal can be communicated over an airlinkand received via receive module 2702 or communicated over the backhaulnetwork and received via I/O interface 2708.

FIG. 22 is a drawing of a flow chart 1700 of an exemplary method ofoperating a wireless device, e.g., a mobile node, in accordance withvarious embodiments. Operation starts in step 1702, where the wirelessdevice is powered on and initialized and proceeds to step 1704, wherethe wireless device establishes a communications link with a basestation. Then, in step 1706, the wireless device monitors for broadcastsignals from the base station while maintaining the link. Operationproceeds from step 1706 to step 1708.

In step 1708, the wireless device checks whether a predetermined changein at least one of said broadcast signals indicative of a change incommunications mode of operation from a cellular mode to a peer to peermode has been detected. In some embodiments, the change in at least oneof said broadcast signals is a change in a beacon signal, e.g., a changein an OFDM beacon signal being transmitted by the base station. In somesuch embodiments, the change includes a change in informationcommunicated by the beacon signal. In various embodiments, theinformation communicated by the beacon signal indicates a peer to peermode of frequency spectrum use after said change. If in step 1708 thewireless device detected a change in a broadcast signal indicative of achange in communications mode of operation from a cellular mode to apeer to peer mode, then operation proceeds from step 1708 to step 1710;otherwise operation proceeds from step 1708 to step 1706 for additionalmonitoring.

In step 1710, the wireless device, in response to detecting the change,ceases to maintain the link. Step 1710 includes sub-step 1710 in whichthe wireless device terminates control signaling used to maintain saidlink. Operation proceeds from step 1710 to step 1714, in which thewireless device starts to maintain transmission silence. Then, in step1716, the wireless device ceases communication with the base station inthe frequency spectrum previously used by the communications link.Operation proceeds from step 1716 to step 1720. In step 1720, thewireless device switches from a cellular mode of operation to a peer topeer mode of operation. Operation proceeds from step 1720 to step 1722.

In step 1727, the wireless device checks for a peer to peer sessioninitiation event. For example, a session initiation event is, e.g., asignal from a peer requesting session establishment, or a decision bythe wireless device to attempt to establish a peer session with anotherwireless terminal detected or known to be in the region. In response toa session initiation event, operation proceeds form step 1722 to step1726, where the wireless device establishes a peer to peercommunications session with another wireless terminal. If a peer to peersession initiation event was not detected, then operation proceeds fromstep 1722 to step 1724, where the wireless device continues to maintaintransmission silence. In some other embodiments, while in the peer topeer mode, the wireless device transmits some broadcast signals, e.g.,some user beacon signals, irrespective of whether or not the wirelessterminal is in a communications session.

Operation proceeds form step 1724 or step 1726 to step 1728, where thewireless device, continues to monitor from signals from the basestation, e.g., broadcast signals such as beacon signals conveyingspectrum usage information. Operation proceeds from step 1728 to step1730. In step 1730, the wireless device determines whether a broadcastsignal indicating a cellular mode of operation was detected. If such asignal was detected, operation proceeds from step 1730 to step 1732,otherwise, operation proceeds from step 1730 to step 1728 for additionalmonitoring.

In step 1732, the wireless device terminates the peer to peercommunications session with said another terminal, if such a session wasestablished. Then, in step 1734, the wireless device re-establishes alink with the base station, e.g., with the wireless device havingremained in the coverage area corresponding to the base station betweenthe time the link ceased to be maintained and the time the link wasre-established.

FIG. 23 is a drawing of an exemplary wireless terminal 2800, e.g.,mobile node in accordance with various embodiments. Exemplary wirelessterminal 2800 can, and sometimes does, switch between a cellularoperation mode and a peer to peer operational mode in response toreceived broadcast signals, e.g., beacon signals. Wireless terminal 2800includes a receiver module 2802, a transmitter module 2804, a processor2806, user I/O devices 2808, and memory 2810 coupled together via a bus2412 over which the various elements may interchange data andinformation. Memory 2810 includes routines 2814 and data/information2816. The processor 2806, e.g., a CPU, executes the routines 2814 anduses the data/information 2816 in memory 2810 to control the operationof the wireless terminal 2800 and implement methods, e.g., a method inaccordance with FIG. 22.

Routines 2814 include a communications routine 2818 and wirelessterminal control routines 2820. The communications routine 2818implements the various communications protocols used by the wirelessterminal 2800. Wireless terminal control routines 2820 include a linkestablishment module 2822, a broadcast signal monitoring module 2824, amodule determination module 2826, a mode control module 2828, a controlsignaling module 2830, a link re-establishment module 2832, and a peerto peer communications establishment module 2834. Mode control module2828 includes switching module 2829.

Data/information 2816 includes detected broadcast signal information2836, detected change in broadcast signal information 2840, determinedmode of operation communicated by broadcast signaling 2842, spectrumusage information 2848, wireless terminal current mode of operationinformation 2844, and generated control signals 2846. Data/information2816 also includes broadcast signals' identification information 2850and broadcast signals' information recovery information 2852. Thebroadcast signals identification information 2850 includes beacon symbolenergy level detection information 2854, and beacon symbol patterninformation 2856. Broadcast signals' information recovery information2852 includes beacon signal to mode mapping information 2858 and beaconsignal to spectrum usage mapping information 2860.

Receiver module 2802, e.g., an OFDM receiver, is coupled to receiveantenna 2803 via which the wireless terminal receives signals. Receivermodule 2802 receives broadcast signals from base stations. The broadcastsignals include, e.g., beacon signaling used to communicate a currentmode of spectrum usage. When the base station is functioning as anaccess node, the wireless terminal receiver 2802 can, and sometimesdoes, receive control signals and user data signals from the basestation in the spectrum. When the spectrum is being utilized for peer topeer communications, the wireless terminal receiver 2802 can, andsometimes does, receive signals directly from a peer wireless terminal,e.g., user beacon signals, peer to peer session establishment signals,and user data signals as part of a peer to peer communication, session.

Transmitter module 2804, e.g., an OFDM transmitter, is coupled totransmit antenna 2805 via which the wireless terminal 2800 transmitssignals. In some embodiments, the same antenna is used by thetransmitter and receiver. Transmitted signals includes, e.g., accessnode based session establishment signals, peer to peer node sessionestablishment signals, control signal to an access node as part ofmaintaining a link with the access node, user data signals to an accessnode, and user data signals to a peer node as part of a peer to peercommunication session.

User I/O devices 2808 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc. User I/O devices 2808 are used foroperations including inputting user data, accessing output user data,and controlling at least some functions and operations of the wirelessterminal, e.g., initiating a communications session.

Link establishment module 2822 establishes a communications link with abase station. Broadcast signal monitoring module 2824 monitors to detectbroadcast signals from base stations. Mode determination module 2826determines a communications mode of operation from at least onebroadcast signal from a base station detected by the monitoring ofmodule 2824. In various embodiments, the broadcast signal from the basestation used by the mode determination module, 2826 for itsdetermination is a beacon signal. In some embodiments, the modedetermination is based on a change in a beacon signal, e.g., asindicated in detected change in broadcast signal information 2840. Insome such embodiments, the change indicates a change in informationcommunicated by the beacon signal. For example, the informationcommunicated by the beacon signal indicates a peer to peer frequencyspectrum use after the change, while the beacon signal informationbefore the change indicates a cellular mode usage of the spectrum. Asanother example, the information communicated by the beacon signalindicates a cellular mode spectrum use after the change, while thebeacon signal information before the change indicates a peer to peermode usage of the spectrum.

Mode control module 2828 controls the wireless terminal 2800 to operatein the mode determined by the mode determination module 2826. The modecontrol module 2828 can, and sometimes does, drop an established linkwith a base station when the mode determination module 2826 indicates achange in a communication mode of operation from a cellular mode to apeer to peer mode of operation. Switching module 2829 switches thewireless terminal 2800 from a cellular mode of operation to a peer topeer mode of operation in response to detecting a predetermined changein at least one of the broadcast signals. Wireless terminal current modeof operation 2844 indicates the current mode of wireless terminaloperation, e.g., cellular mode or peer to peer mode, into which thewireless terminal has been switched.

Control signaling module 2830 generates control signals 2846 to maintainan established link with a base station. Generated control signals 2846include, e.g., power control signals, timing control signals, controlchannel report signals such as SNR reports, etc. When the mode controlmodule 2828 drops an established link with a base station, the modecontrol module 2828 controls the control signaling module 2830 to stopgenerating control signals used to maintain the link.

Link re-establishment module 2832 re-establishes a link with a basestation in response to detecting a broadcast signal indicating acellular mode of operation. Peer to peer communications establishmentmodule 2834 is used to establish a peer to peer communications sessionwith another wireless terminal, e.g., during at least a portion of thetime between which said link is ceased to be maintained with the basestation and the link is re-established with the base station.

Detected broadcast signal information 2836, e.g., detected beacon signalinformation is an output of broadcast signal monitoring module 2824.Broadcast signal monitoring module 2824 uses the data/information 2816including the broadcast signals' identification information 2850 todetect beacon signals. Beacon symbol energy level detection information2854 includes energy level criteria used for identifying beacon symbolsfrom among a plurality of received signals. For example, a beacon signalincludes a beacon signal burst including at least a beacon symbol andthe beacon symbol is transmitted at a relatively high energy level withrespect to other signals transmitted by the base station, facilitatingeasy detections by a wireless terminal. Beacon symbol patterninformation 2856 includes information identifying sets of beacon symbolswithin a set of beacon symbol transmission units. For example, aparticular pattern of beacon symbols may, and sometimes does represent aparticular beacon signal.

Mode determination module 2826 uses the data/information 2816 includingthe broadcast signals' information recovery information 2852 todetermine a mode of operation being communicated by the broadcast signal2842, e.g., one of a cellular mode and a peer to peer mode, and spectrumusage information 2848, e.g., one of a cellular mode spectrum allocationand a peer to peer mode, spectrum allocation. In some embodiments thecellular mode spectrum usage information further identifies one of atime division duplex use of spectrum and a frequency division duplex useof spectrum. For example, the base station when functioning as an accessnode may operate in a TDD manner in which the spectrum is alternatelyused for dowlink and uplink, or the base station may operate using twodistinct bands for uplink and downlink which allow simultaneous uplinkand downlink signaling.

FIG. 24 is a drawing of a flowchart 1800 of an exemplary method ofoperating a mobile communications device in a system including a basestation in accordance with various embodiments. Operation starts in step1802, where the mobile communications device is powered on andinitialized and proceeds to step 1804. In step 1804, the mobilecommunications device determines a base station mode of operation, thebase station mode of operation being one of an access mode of operationin which the base station operates as a network access node and a peerto peer mode of operation in which devices within a base stationcoverage area are allowed to communicate directly with one another.Operation proceeds from step 1804 to step 1806.

In step 1806, the mobile communications device, sends a signal to a basestation to signal a wireless terminal desired change in the mode of basestation operation. Then, in step 1808, the mobile communications devicemonitors for a broadcast signal from the base station indicating achange in base station mode of operation to the indicated mode desiredby the mobile communications device. Operation proceeds from step 1808to step 1810. In step 1810, the mobile communications device checks ifthe monitored for signal has been detected. If the monitored for signalwas detected, then operation proceeds from step 1810 to step 1812;otherwise, operation proceeds from step 1810 to step 1808 for additionalmonitoring. In some embodiments, a timeout is associated with theduration of the monitoring, and if the mobile communications device doesnot receive the monitored for signal within the allocated time, themobile communications device needs to resend the desired change signal.

In step 1812, the mobile communications device changes the mode of themobile communications device operation to the mode to which, the basestation has changed. Operation proceeds from step 1812 to step 1814. Instep 1814, the mobile communications device signals the base station toswitch from the indicated mode of operation to the base station'sprevious mode of operation.

In some embodiments, the signal of step 1804 indicates a desire for achange from a network access mode of operation to a peer to peer mode ofoperation. In some embodiments, the signal of step 1804 includesinformation indicating a level of authority said mobile communicationsdevice has to control the base station operation. In some suchembodiments, the information indicating the level of authority is one ofa device identifier, user identifier, and priority level indicator.

In various embodiments, the mobile communications device is a deviceused by a government agent with authority to override use of thespectrum used by the base station.

In some embodiments, the mobile communications device is a cellularnetwork device, and the desired change of step 1806 is a change from apeer to peer mode to a network mode of operation. In some suchembodiments the cellular network device does not support peer to peeroperation.

In various embodiments, the mobile communications device is a peer topeer device and the desired change is a change from a network accessmode to a peer to peer mode of operation. In some such embodiments, thepeer to peer device does not support a cellular network mode ofoperation, In some embodiments the peer to peer device which does notsupport a cellular network mode of operation is a device used by agovernment agent with authority to override the use of the spectrum bythe base station.

FIG. 25 is a drawing of an exemplary wireless terminal 2900, e.g.,mobile node, in accordance with various embodiments. Exemplary wirelessterminal 2900 includes the capability to influence a base station's modeof operation, e.g., requesting and/or commanding switching, between acellular mode and a peer to peer mode.

Exemplary wireless terminal 2900 includes a receiver module 2902, atransmitter module 2904, a processor 2906, user I/O devices 2908, andmemory 2910 coupled together via a bus 2912 over which the variouselements may exchange data and information. Memory 2910 includesroutines 2914 and data/information 2916. The processor 2906, e.g., aCPU, executes the routines 2914 and uses the data/information 2916 inmemory 2910 to control the operation of the wireless terminal andimplement methods, e.g., a method in accordance with FIG. 24.

Routines 2914 include communications routine 2918 and wireless terminalcontrol routines 2920. The wireless terminal control routines 2920include a base station mode of operation determination module 2922, asignal generation module 2924, a broadcast signal detection module 2922,and a communications mode control module 2930. The signal generationmodules 2924 includes a base station mode restoration module 2926.

Data/information 2916 includes a determined base station mode ofoperation 2932, a generated change signal 2934, and stored informationindicating the level of authority the wireless terminal has to controlthe base station operations 2936. Information 2936 includes a wirelessterminal device identifier 2938, a wireless terminal user identifier2940, and a priority level indicator 2942. Data/information 2916 alsoincludes detected broadcast signal information 2944 and current mode ofwireless terminal operation information 2946.

The receiver module 2902, e.g., an OFDM receiver, is coupled to receiveantenna 2903, via which the wireless terminal 2900 receives signals.Received signals include received broadcast signals, e.g., beaconsignals, from a base station from which a base station mode of operationcan be determined.

Transmitter module 2904, e.g., an OFDM transmitter, is coupled totransmit antenna 2905, via which the wireless terminal 2900 transmitssignals. Transmitted signals include generated change signal 2934conveying a wireless terminal 2900 desire for a base station to changeits mode of operation. Transmitter module 2904 sends the generatedchange signal 2934 to the base station to communicate the wirelessterminal's desired change in the base station's mode of operation. Thegenerated change signal 2934 can be, and sometimes is, a request for thebase station to change modes. The generated signal 2934 can be, andsometimes is, a command to the base station to change its mode ofoperation.

User I/O devices 2908 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc. User I/O devices 2908 are used foroperations including inputting user data, accessing output user data,and controlling at least some functions and operations of the wirelessterminal, e.g., initiating a communications session. In someembodiments, the user I/O devices 2908 include a special purpose key,switch or button, for use to command a mode switch of the base station.For example, the wireless communications device 2900 is used by agovernment agent with authority to override use of the spectrum by thebase station and includes a special purpose button on the wirelessterminal, which when depressed, initiates the generation andtransmission of a mode change control signal directed to the basestation.

Communications routine 2918 implements the various communicationsprotocols used by the wireless terminal 2900. Base station mode ofoperation determination module 2922 determines a base station's mode ofoperation, the base station mode of operation being one of an accessnode mode of operation in which the base station operates as a networkaccess node and a peer to peer mode of operation in which devices withina base station coverage area are allowed to communicate directly withone another. Determined base station mode of operation 2932 is an outputof determination module 2922.

Signal generation module 2924 generates a signal change signal 2934indicating a wireless terminal desired change in the base station's modeof operation. At times, the generated change signal 2934 indicates adesire for a change from a network access mode of operation to a peer topeer mode of operation. At times, the generated change signal 2934indicates a desire for a change from a peer to peer mode of operation tonetwork access mode of operation.

In some embodiments, the change signal conveys a level of authorityassociated with the change signal. The level of authority, in someembodiments, is based on one or more of wireless terminal identifier,user identifier and a priority level indicator. In some embodiments,wireless terminal 2900 has a fixed level of authority associated withthe device. In some embodiments, wireless terminal 2900 has a variablelevel of authority, e.g., which changes a function of useridentification information and/or priority level access codeinformation. In some such embodiments, the user I/O devices 2908 includea biometric input device for receiving biometric informationcorresponding to the user, the input biometric information being used toobtain/authenticate authorization information.

Base station mode restoration module 2926 generates a restoration signal2935 to be communicated to a base station, the restoration signal tosignal the base station to switch from the indicated mode of operationcommunicated by the previous change signal to the base station, theindicated mode being the mode in which the base station is currentlyoperating, to the previous mode of base station operation.

Broadcast signal detection module 2928 detects a broadcast signal whichindicates that the base station has changed the base station mode ofoperation to an indicated mode of operation desired by the wirelessterminal. Detected broadcast signal information 2944 is an output ofdetection module 2928. In various embodiments, the detected broadcastsignals are beacon signals, e.g., OFDM beacon signal.

Communications mode control module 2930 changes the operational mode ofthe mobile communications device, as indicated by current mode ofwireless terminal operation, to match the mode of base station operationto which the base station has transitioned as indicated by a detectedbroadcast signal. In various embodiments, the wireless terminal 2900supports communications sessions in both cellular, e.g., access nodebased mode and peer to peer mode. In some embodiments, the wirelessterminal does not support communications sessions in one of the cellularand peer to peer modes of operation. In some such embodiments, thewireless terminal enters a standby state while the spectrum is allocatedfor the node in which the wireless terminal can not participate in acommunication session, e.g., conserving power.

In some embodiments, the wireless terminal 2900 is a device used by agovernment agent with the authority to override use of the spectrum usedby a base station. In some embodiments, the wireless terminal 2900 is acellular network device, and the wireless terminal indicates a desiredchange from a peer to peer to a network access mode of operation. Insome such embodiment, the cellular network device does not support peerto peer communications. In some embodiments, the wireless terminal 2900is a peer to peer device, and the wireless terminal indicates a desiredchange from a network access mode of operation to a peer to peer mode ofoperation. In some such embodiments, the cellular network device doesnot support, a cellular network mode of operation. In some embodiments,the wireless terminal is a mobile communications device used by agovernment agent with authority to override use of the spectrum by thebase station.

In one embodiment, which is a variation based on wireless terminal 2900,the wireless terminal is a mobile communications device used by agovernment agent with the authority to override the use of spectrum bythe base station, and the device communicates mode change commandsignals but does not support either access node based or peer to peerbased communications sessions.

FIG. 26 is a drawing of a flowchart 1900 of an exemplary method ofoperating a wireless device, e.g., a mobile node, in accordance withvarious embodiments. Operation starts in step 1902, where the wirelessdevice is powered on and initialized. Operation proceeds from start step1902 to step 1904, where the wireless device receives a first broadcastsignal from a base station. Then, in step 1906, the wireless devicedetermines from the received first broadcast signal that a frequencyband corresponding to the base station is being used for peer to peercommunications. Operation proceeds from step 906 to step 1908.

In step 1908, the wireless device receives a second broadcast signalfrom the base station, and then in step 1910, the wireless devicedetermines from the received second broadcast signal that the secondfrequency band has been changed to be used as a cellular network band.In response to determining that the frequency band is to be used as acellular frequency band, operation proceeds from step 1910 to one ofalternate steps 1912, 1914, and 1916. In alternative step 1912, thewireless device reduces transmission power. In some embodiments,reducing transmission power includes a reduction in transmission powerby at least 10 dBs. In some embodiments, reducing transmission powerincludes ceasing to transmit. In alternative step 1914, the wirelessdevice terminates an ongoing peer to peer communications session. Inalternative step 1916, the wireless device puts an ongoing peer to peercommunications session into a hold state. Operation proceeds from any ofsteps 1912, 1914, 1916 to step 1918. If the wireless terminal does nothave an ongoing peer to peer communications session when making thedetermination of step 1910, operation proceeds from step 1910 to step1918 without traversing alternative steps 1912, 1914, or 1916.

In step 1918, the wireless device receives a third broadcast signal fromthe base station, and then in step 1920, the wireless device determinesfrom the third broadcast signal that said frequency band has beenchanged to be used for peer to peer communications. Operation proceedsfrom step 1920 to step 1922, where the wireless device switches a peerto peer communications session, which was in hold state, if one happensto exist in hold state, to an active state in response to said thirdbroadcast signal.

In some embodiments at least some of the received first, second andthird broadcast signals include beacon signal bursts. In someembodiments, each of the first, second, and third signals are OFDMbeacon signals.

FIG. 27 is a drawing of an exemplary wireless terminal, e.g., mobilenode, implemented in accordance with various embodiments. Exemplarywireless terminal 3000 supports peer to peer communications sessions. Insome embodiments, exemplary wireless terminal 3000 supports peer to peercommunications but does not support a cellular mode of operation.Exemplary wireless terminal 3000 includes a receiver module 3002, atransmission module 3004, a coupling module 3003, a processor 3006, userI/O devices 3008, a power supply module 3010 and memory 3012 coupledtogether via a bus 3014 over which the various elements may interchangedata and information. Memory 3012 includes routines 3016 anddata/information 3018. The processor 3006, e.g., a CPU, executes theroutines and uses data/information 3018 in memory 3012 to control theoperation of the wireless terminal 3000 and implement methods, e.g., amethod in accordance with FIG. 26.

Coupling module 3003, e.g., a duplex module, couples the receiver module3002 to antenna 3005 and the transmission module 3004 to antenna 3005,e.g., coordinating time division duplex operations of wireless terminal3000. Power supply module 3012, which includes a battery 3011, is usedto power up the various components of the wireless terminal 3000. Poweris distributed from the power supply module 3010 to the variouscomponents (3002, 3003, 3004, 3006, 3008, 3012), via a power bus 3009.User I/O devices 3008 include, e.g., keypad, keyboard, switches, mouse,microphone, speaker, display, etc., User I/O devices 3008 are used foroperation including inputting user data, accessing output user data, andcontrolling at least some functions and operations of the wirelessterminal, e.g., initiating a peer to peer communications session.

Routines 3016 include a mode determination module 3020, a mode controlmodule 3022, a peer to peer communications session termination module3024, a session hold module 3026, and a peer to peer communicationssession reestablishment module 3028. Data/information 3018 includesreceived broadcast signals 3030, a determined mode of communicationsoperation 3032, wireless terminal controlled mode information 3034, acurrent level of transmission power information 3035, power reductioninformation 3036, 1^(st) maximum transmission power level information3038, 2^(nd) maximum transmission power level information 3040, and peerto peer communications session information 3042. The peer to peercommunications session information 3042 includes status information3044, peer node information 3046, user data information 3048, and stateinformation 3050.

Receiver module 3002, e.g., an OFDM receiver, receives signals includingbroadcast signals. Receiver module 3002 also receives, at times, userdata signals from a peer wireless terminal in a peer to peercommunications session with wireless terminal 3000. Received broadcastsignals 3030, e.g., beacon signals, are used to determine a mode ofcommunication band operation.

Transmitter module 3004, e.g., an OFDM transmitter, transmits user dataas part of a peer to peer communications session. In some embodiments,transmission module 3004 also transmits user beacon signals e.g. OFDMuser beacon signals.

Mode determination module 3020 determines based on received broadcastsignals 3030 a mode of communications band operation, determined mode ofcommunications band operation 3032. The determined node ofcommunications band operation indicating a mode of operation in whichthe frequency band is to be used at a point in time, the determined modeof communication band operation being one of a plurality of frequencyband modes including at least a cellular communications mode and a firstpeer to peer communications mode.

Modes control module 3022 controls wireless terminal 3000 deviceoperation as a function of at least one of a mode determination and achange in a determined mode of communications band operation, said modecontrol module 3022 controlling the transmitter to reduce power inresponse to determining that the frequency band is to be used as acellular frequency band. In some embodiments, the controlling thetransmitter to reduce power includes reducing transmission power by atleast 10 dBs. In some embodiments reducing transmission power includesceasing to transmit.

Thus, in some embodiments, when wireless terminal 3000 is in a peer topeer communications session and the spectrum is reallocated to supportaccess node based operations, the wireless terminal is permitted tocontinue the peer to peer communications session at a reduced powerlevel. While, in other embodiments, when wireless terminal 3000 is in apeer to peer communications session and the spectrum is reallocated foraccess node based operation, the wireless terminal terminates orsuspends the peer to peer communications session until the spectrum isreallocated for peer to peer usage. In some embodiments, wirelessterminal 3000 decides whether to continue with, terminate, or place onhold a peer to peer session interrupted by a spectrum reallocation, inresponse to other factors, e.g., device identification information, useridentity information, priority information, latency requirements, etc.

Peer to peer communications session termination module 3024 terminate atleast some peer to peer communications sessions in response to adetermination that a frequency band is being used as a cellularfrequency band. Session hold module 3026 puts an ongoing peer to peercommunications session into a hold state in response to a determinationthat the frequency band is being used as a cellular frequency band. Peerto peer communications session reestablishment module 3028 transitions apeer to peer communications session from a hold state to at active statein response to a determination that the frequency band is to be used forpeer to peer communications.

Current level of transmission power information 3035 is a monitoredlevel used by mode control module 3022, when determining a transmissionpower level reduction in accordance with power reduction information3036, e.g., a gain factor of at least 10 dBs, and 1^(st) maximumtransmission power level information 3038 and 2^(nd) maximum leveltransmission power information 3040. The power level reduction is inresponse to a detection that spectrum usage is changing from peer topeer to cellar based, and the wireless terminal 3000 continuing with thepeer to peer communications session at a reduced power level. In someembodiments, the mode control module 3022 supports 1^(st) and 2^(nd)modes of peer to peer operation from the perspective of the wirelessterminal, the second peer to peer mode of operation being a reducedpower level mode of operation in which the wireless communicationsdevice 3000 uses a lower maximum transmission power level for thetransmission of user data than is used in the 1^(st) mode of peer topeer operation. In some embodiments, the 1^(st) mode of wirelessterminal peer to peer operation applies when the spectrum is allocatedfor peer to peer usage, and the second mode of wireless terminal peer topeer operation applies when the spectrum is allocated primarily forcellular access node base operations.

Status information 3044 indicates whether the peer to peercommunications session is in an active state or a hold state. Statusinformation 3044 also indicates whether the peer to peer communicationssession is in a first mode of wireless terminal peer to peer operation,e.g., normal power mode, or a second mode of wireless terminal peer topeer operation, reduced power mode. Peer node information 3046 includespeer node identification information, addressing information, andpriority level information. User data information 3048, e.g., voice,image, text, file information, includes user data to be transmitted andreceived as part of the peer to peer communications session. Stateinformation 3050 includes session maintenance information, and storedinformation used to reestablish a session placed into a hold state.

FIG. 28 comprising the combination of FIG. 28A and FIG. 28B is a drawingof a flowchart 2000 of an exemplary communications method in accordancewith various embodiments. Operation of the exemplary communicationsmethod starts in step 2002 and proceeds to step 2004, step 2024 viaconnecting node A 2006, and step 2030 via connecting node B 2008.

In step 2004, a first wireless terminal capable of supporting peer topeer operations and cellular network operations is operated. Step 2004includes sub-steps 2010, 2011, 2012, 2014, 2016, 2018, and 2020. Insub-step 2010, the first wireless terminal monitors for paging signalsfrom a base station during a first set of time intervals which arepaging time intervals. In various embodiments, during the first set oftime intervals the first wireless terminal does not transmit peer topeer signals. In some embodiments, during the first set of timeintervals the first wireless terminal also does not receive peer to peersignals.

In sub-step 2012, the first wireless terminal, during a second set oftime intervals, which do not overlap said first set of time intervals,is operated to participate in a peer to peer communications session. Insome embodiments, the first and second time intervals are interleaved.Sub-step 2012 includes sub-step 2022, in which the first wirelessterminal, during at least a portion of said second set of time intervalsis operated to transmit a first wireless terminal identifier used forpeer to peer communications. In some such embodiments, the firstwireless terminal identifier is communicated via a user beacon signal,e.g., an OFDM user beacon signal including a beacon signal burstincluding at least one beacon symbol.

In some embodiments, the same frequency band is used for paging and forpeer to peer communications, and the first wireless terminal need notperform sub-step 2011. In some embodiments, different frequency bandsare used for paging and for peer to peer communications. In some suchembodiments, sub-step 2011 is performed in which the first wirelessterminal switches the frequency band of a receiver in said wirelessterminal when switching between monitoring for pages during a first timeinterval and operating in a peer to peer mode during a second timeinterval.

Returning to sub-step 2010, for a detected page signal directed to thefirst wireless terminal, operation proceeds from sub-step 2010 tosub-step 2014. In sub-step 2014, the first wireless terminal decideswhether to establish a link with the base station in response to thepage directed to the first wireless terminal or to continue with anongoing peer to peer communication session. In some embodiments, thedecision of the step 2014 is a function of at least one of: a prioritylevel associated with the ongoing peer to peer communications session, apriority level associated with the peer wireless terminal in the ongoingpeer to peer communications session, a priority level associated withthe user of the peer wireless terminal in the ongoing peer to peercommunication session, the type of data being communicated in the peerto peer communications session, latency considerations of the data beingcommunicated in the peer to peer session, an estimate of the amount ofdata remaining to be communicated in the peer to peer communicationssession, and priority information communicated in the page signal. Insome such embodiments, the decision of step 2014 is a function of atleast two of: a priority level associated with the ongoing peer to peercommunications session, a priority level associated with the peerwireless terminal in the ongoing peer to peer communications session, apriority level associated with the user of the peer wireless terminal inthe ongoing peer to peer communication session, the type of data beingcommunicated in the peer too peer communications session, latencyconsiderations of the data being communicated in the peer to peersession, an estimate of the amount of data remaining to be communicatedin the peer to peer communications session, and priority informationcommunicated in the page signal.

If the decision of sub-step 2014 is to establish a link with the basestation which transmitted the page, then operation proceeds to sub-step2016, where the first wireless terminal terminates the peer to peercommunications session and in sub-step 2018 establishes a link with thebase station. However, if the first wireless terminal decides insub-step 2014 to continue with the ongoing peer to peer communicationsession, operation proceeds from sub-step 2014 to sub-step 2020 wherethe first wireless terminal continues with the peer to peercommunications session. In some such embodiments, the first wirelessterminal, when deciding to perform sub-step 2020, the first wirelessterminal ignores the page, e.g., with no response back to the basestation. In other embodiments, the first wireless terminal, whendeciding to perform sub-step 2020, sends a page response signal to thebase station indicating the first wireless terminal has received thepage but has decided not to establish a link with the base station.

Returning to step 2024, in step 2024, a second wireless terminal,capable of supporting peer to peer mode operations and cellular networkoperations, is operated. Step 2024 includes sub-steps 2026 and 2028. Insub-step 2026 the second wireless terminal monitors for paging signalsfrom a base station during a third set of time intervals which arepaging time intervals. In some such embodiments, the first and thirdpaging time intervals overlap. In sub-step 2028, the second wirelessterminal, during said second set of time intervals, which does notoverlap with said first or third set of time intervals participates in apeer to peer communications session.

Returning to step 2030 in step 2030, a third wireless terminal isoperated in a peer to peer communications session during which at leastsome first time periods occur, wherein the third wireless terminal doesnot perform paging operations between the start and end of its peer topeer communications session and remains silent during the first timeintervals occurring between the start and end of its peer to peercommunications session.

FIG. 29 is a drawing of an exemplary wireless terminal 3100, e.g.,mobile node, in accordance with various embodiments. Exemplary wirelessterminal 3100 monitors for, detects, and processes paging signals in awireless communications system including dual mode capability includingaccess node based cellular communications and peer to peercommunications, and exemplary wireless terminal 3100 supports operationin both modes of operation.

Exemplary wireless terminal 3100 includes a receiver module 3102, atransmitter module 3104, a processor 3106, user I/O devices 3108, andmemory 3110 coupled together via a bus 3112 over which the variouselements may exchange data and information. User I/O devices 3108include, e.g., keypad, keyboard, switches, mouse, microphone, speaker,display, etc. User I/O devices 3108 are used for operation includinginputting user data, accessing output user data, and controlling atleast some functions and operations of the wireless terminal, e.g.,initiating a peer to peer communications session or initiating an accessnode based communications session.

Receiver module 3102, e.g., an OFDM receiver, coupled to receive antenna3103 via which the wireless terminal receives signals from a basestation including paging signals and signals in which the base stationis functioning as a point of network attachment for wireless terminal3100, e.g., downlink control signals and downlink user data signals.Receiver module 3102 also receives signals from a peer node in a peer topeer communications session with wireless terminal 3100.

Transmitter module 3104, e.g., an OFDM transmitter, is coupled totransmit antenna 3105, via which the wireless terminal 3100 transmitssignals. Transmitted signals include generated identification signals3142, e.g., an OFDM user beacon signal including beacon signal burst,each beacon signal burst including at least one OFDM beacon symbol.Transmitted signals also include access node based session establishmentsignals, peer to peer session establishment signals, control and userdata uplink signals directed to a base station serving as the wirelessterminal's point of network attachment, signals directed to a peer nodeas part of a peer to peer communications session, and uplink pageresponse signals directed to the base station which transmitted the pagedirected to wireless terminal 3100.

Memory 3110 includes routines 3114 and data/information 3116. Theprocessor 3106, e.g., a CPU, executes the routines 3114 and uses thedata/information 3116 in memory 3110 to control the operation of thewireless terminal and implement methods. Routines 3114 include acommunications routine 3118 and wireless terminal control routines 3120.The communications routine 3118 implements the various communicationsprotocols used by the wireless terminal 3100. The wireless terminalcontrol routines 3120 include a time interval determination module 3122,a cellular network communications module 3124, a page signal monitoringmodule 3126, a peer to peer communications module 3128, a wirelessterminal identification signal generation module 3130, a decision module3132, and a peer to peer communications session termination module 3134.The peer to peer communications module 3128 includes a peer to peercommunications control module 3129.

Data/information 3116 includes a determined first set of time intervals3136, which are paging time intervals, a determined second set of timeintervals 3138, a detected page signal 3140, a generated wirelessterminal identification signal, e.g., a generated user beacon associatedwith wireless terminal 3100, paging band information 3144, peer to peerband information 3146 and receiver band setting information 3148.

Time interval determination module 3122 determines first and second setsof time intervals (3136, 3138), respectively), the first and second setsof time intervals being non-overlapping, sets, the first set of timeintervals being paging time intervals. Cellular network communicationsmodule 3124 supports cellular network communications operations, e.g.,operations in which the wireless terminal uses the base station as anetwork attachment point to communicate with another wireless terminalvia the cellular communications network. Page signal monitoring module3126 monitors for paging signals from a base station during the firstset of time intervals 3136. Information 3140 represents a detected pagesignal directed to wireless terminal 3100.

Peer to peer communications module 3128 supports peer to peercommunications signaling operations during the second set of timeintervals 3138 but not during the first set of time intervals 3136. Peerto peer transmission control module 3129 restrains the wireless terminalfrom transmitting peer to peer signals during the first time intervals.In some embodiments, the wireless terminal is also controlled to suspenddetection operations of peer to peer signals during the first timeintervals. In various embodiments, members of the first set of timeintervals are interleaved with members of the second set of timeintervals.

Wireless terminal identification signal generation module 3130 generatesa wireless terminal identifier 3142 used for peer to peercommunications, e.g., an OFDM beacon signal burst or sequence of bursts,each beacon signal burst including at least one beacon symbol. Decisionmodule 3132 decides between establishing a communication link with abase station in response to a page which was received or continuing withan on-going peer to peer communications session. Peer to peercommunications session termination module 3134 terminates a peer to peercommunications session in response to a received page directed to thewireless terminal 3100.

Paging band information 3144 includes information identifying thefrequency band used for paging, while peer to peer band information 3146identifies the frequency band used for peer to peer communications. Insome embodiments the same frequency band is used for paging and peer topeer communications. In some embodiments, different frequency bands areused for paging and peer to peer communications. In some suchembodiments, receiver module 3102 includes a tunable receiver responsiveto a mode control signal for switching between the different frequencybands used for paging and peer to peer communications. Receiver bandsetting information 3148 includes information indicating the currentsetting of the receiver module 3102 and control signaling used to changethe setting of the receiver module 3102.

FIG. 30 is a drawing of an exemplary communications system 2100 inaccordance with various embodiments. Exemplary communications system2100 includes a plurality of base stations (base station 1 2102, basestation 2 2104, base station 3 2106) and a plurality of non-accessbeacon signal transmitter nodes (non-access beacon signal transmitternode 1 2108, non-access beacon signal transmitter node 2 2112,non-access beacon signal transmitter node 3 2110). The base stations(2102, 2104, 2106) are coupled to network nodes (2114, 2118, 2118) vianetwork links (2120, 2128, 2126), respectively. In addition, system 2100includes network node 2116 which is coupled to (network node 2114,network node 2118, non-access beacon signal transmitter 2108, and othernetwork nodes and/or the Internet) via network links (2122. 2124, 2130,2131), respectively. Network links (2120, 2122, 2124, 2l26, 2128, 2130,2131) are, e.g., fiber optic links and/or wired links.

Some of the base stations (BS 1 2102, BS 2 2104) support both peer topeer communications in the base station region and also operate asaccess nodes. Base station 3 2106 functions as an access node and doesnot support peer to peer communications in its coverage region. Eachbase station (BS 1 102, BS 2 2104, BS 3 2106) has a corresponding region(2103, 2105, 2107) which represents a cellular coverage area when in thenetwork access mode. Regions (2103, 2105) also represent base stationbeacon transmission regions when supporting peer to peer communications.

The base stations (2102, 2104, 2106) and the non-access beacon signaltransmitter nodes (2108, 2110, 2112) transmit beacon signals includingbeacon signal bursts, e.g., OFDM beacon signal bursts each beacon signalburst including at least one beacon symbol.

Exemplary system 2100 also includes a plurality of wireless terminals,e.g., mobile nodes, (MN 1 2150, MN 2 2152, MN 3 2154, MN 4 2156, MN 52158 MN 6 2160, MN 7 2162, MN 8 2164), which may move throughout thesystem. MN 1 2150 is using BS 1 2102 as an access node and is coupled toBS 1 2102 via link 2166. MN 2 2152 is using BS 1 2102 as an access nodeand is coupled to BS 8 2102 via link 2168. MN 1 2150 and MN 2 2152 areusing access node beacon signals transmitted from BS 1 2102 forsynchronization. MN 3 2154 is in a peer to peer communications sessionwith MN4 2156 using peer to peer link 2170. MN 3 2154 and MN 4 2156 areusing peer to peer beacon signals from BS 1 2102 for synchronizationpurposes.

MN 5 2158 is using BS 3 2106 as an access node and is coupled to BS 32106 via link 2172. MN 6 2160 is using BS 3 2106 as an access node andis coupled to BS 3 2106 via link 2174. MN 5 2158 and MN 6 2160 are usingaccess node beacon signals transmitted from BS 3 2174 forsynchronization.

MN 7 2162 is in a peer to peer communications session with MN 8 2164using peer to peer link 2176. MN 7 2162 and MN 8 2164 are using peer topeer beacon signals from non-access beacon signal transmitter node 32110 for synchronization purposes.

Base station 1 2102 includes a peer to peer beacon signal generationmodule 2132, an access node beacon signal generation module 2134, atransmitter module 2136, a receiver module 2138 and a switching module2140. Peer to peer beacon signal generation module 2132 generates beaconsignals used to support peer to peer communications, while access nodebeacon signal generation module 2134 generates beacon signals used tosupport cellular network communications. Transmitter module 2136, e.g.,an OFDM transmitter, transmits generated peer to peer beacon signals andgenerated access node beacon signals. Transmitter module 2136 alsotransmits control and user data signals to wireless terminals whenfunctioning as an access node. Receiver module 2138, e.g., an OFDMreceiver, receives signals such as access request signals, controlsignals and user data from wireless terminals, e.g., mobile nodes usingthe base station as a point of network attachment. Switching module 2140supports switching between peer to peer and cellular modes of operationusing the same frequency band for peer to peer and cellular modes ofoperation at different times. Base station 1 2102 transmits differentbeacon signals during peer to peer and cellular modes of operation.

Non-access beacon signal transmitter node 2 2112 and non-access beaconsignal transmitter node 3 2110 are standalone devices. Non-access beaconsignal transmitter node 2 2112 includes a transmitter 2142, a battery2144 and a receiver 2146. Battery 2144 powers non-access beacon signaltransmitter node 2 2112. Transmitter 2142 transmits beacon signals whichare utilized by mobile nodes in its transmitter coverage region 2113 forsynchronization purposes in supporting peer to peer communicationssessions. The beacon signal transmitter 2142 does not relay any userdata. Receiver 2146 receives a broadcast signal used for timingsynchronization purposes. The receiver 2146 for receiving a broadcastsignal used for timing synchronization purposes is one of a GSMreceiver, a satellite receiver, and a cellular network receiver.Satellite receivers include e.g., a GPS receiver, broadcast TV and/orradio signal satellite receiver, proprietary satellite receiver orgovernment controlled satellite receiver. Cellular network receiversinclude e.g., CDMA, OFDM, GSM, etc., receivers. In some embodiments, anon-access beacon signal transmitter node includes a plurality ofdifferent types of receivers for receiving different types of broadcastsignals, e.g., with different signals being available in some areas butnot in others.

In various embodiments, at least some of the base stations, whichtransmit beacon signals are not synchronized with respect to oneanother. In various embodiments, at least some of the non-access beacona signal transmitter nodes, which transmit beacon signals, are notsynchronized with respect to one another. For example, non-access beaconsignal transmitter node 3 2110, in some embodiments, does not include areceiver, and its transmitted beacon signals into its transmitter region2111 are free running with respect to the other non-access beacon signaltransmitters in system 2100 and the base stations in system 2100.

Non-access beacon signal transmitter module 3 2110 includes a solar cell2148, and the solar cell 2148 is a solar power source conversion devicefor powering non-access beacon signal transmitter node 3 2110 during atleast some of the time.

Non-beacon access beacon signal transmitter node 1 2108 is coupled tothe network via link 2130 thus facilitating timing synchronizationinformation to be communicated to the node 2108 allowing for its beaconsignal transmission into its transmitter region 2109 to be synchronizedwith respect to an overall system timing reference. No user data iscommunicated over link 2130.

FIG. 31 is a drawing of an exemplary wireless communications system 2200which supports both peer to peer communications and cellularcommunications in accordance with various embodiments. Exemplarycommunications system 2200 includes a plurality of wireless terminals,e.g., mobile nodes, and a plurality of base stations. At least some ofthe plurality of base stations are both network access node and peer topeer capable such as exemplary base station 2212. Exemplarycommunications system 2220 also includes some base stations whichfunction as access nodes but do not support peer to peer communicationssuch as exemplary base station 2280 and some non-access beacon signaltransmitter nodes for supporting peer to peer communications such asexemplary non-access beacon signal transmitter node 2282.

System 2200 includes wireless terminal 1A 2202 and wireless terminal 1B2204, which both support peer to peer and cellular communications;wireless terminal 2A 2206 and wireless terminal. 2B 2210, which bothsupport peer to peer communications but not cellular networkcommunications; and wireless terminal 3 2208 which supports cellularnetwork communications but not peer to peer communications.

Wireless terminal 1A 2202 includes a beacon signal processing module2216, a peer to peer communications module 2218, a cellular networkcommunications module 2230, a mode control module 2232, current modeinformation 2234 and subscriber plan identification information 2236.Beacon signal processing module 2216 processes beacon signals receivedfrom base stations and/or non-access beacon signal transmitter nodes.The beacon signals are uses for supporting cellular and peer to peercommunications, e.g., providing synchronization, identification, modeand/or priority information. Peer to peer communications module 2218performs operations supporting peer to peer communications. Cellularnetwork communications module 2230 performs operations supportingcellular communications in which the wireless terminal 1A 2202 iscommunicating via a wireless communications link with a base stationfunctioning as an access node and providing a point of networkattachment. Mode control module 2232 switches between peer to peer andcellular modes of operation, as wireless terminal 1A 2202 supports atmost one of peer to peer mode and cellular mode operation at a giventime. Current mode information 2234 indicates which of the peer to peermode and cellular mode wireless terminal 1A 2202 is currently operatingin.

Wireless terminal 1B 2204 includes a beacon signal processing module2238, a peer to peer communications module 2240, a cellular networkcommunications module 2242, a communications control module 2244, andsubscriber plan identification information 2246. Beacon signalprocessing module 2238 processes beacon signals received from basestations and/or non-access beacon signal transmitter nodes. Peer to peercommunications module 220 performs operations supporting peer to peercommunications. Cellular network communications module 2242 performsoperations supporting cellular communications in which the wirelessterminal 1B 2204 is communicating via a wireless communications link,with a base station functioning as an access node and providing a pointof network attachment. Communications control module 2244 switchesbetween peer to peer and cellular modes of operation, as wirelessterminal 1A 2202 controls the wireless terminal to maintain peer to peerand cellular network communications sessions at the same time.

Wireless terminal 2A 2206 includes a beacon signal processing module2248, a peer to peer communications module 2250, and subscriber planidentification information 2252. Beacon signal processing module 2248processes beacon signals received from base stations and/or non-accessbeacon signal transmitter nodes. Peer to peer communications module 2250performs operations supporting peer to peer communications. Wirelessterminal 2B 2210 includes a beacon signal processing module 2260, a peerto peer communications module 2262, and subscriber plan identificationinformation 2264. Beacon signal processing module 2260 processes beaconsignals received from base stations and/or non-access beacon signaltransmitter nodes. Peer to peer communications module 2262 performsoperations supporting peer to peer communications.

Wireless terminal 3 2208 includes a beacon signal processing module2254, a cellular network communications module 2256, and subscriber planidentification information 2258. Beacon signal processing module 2254processes beacon signals received from base stations and/or non-accessbeacon signal transmitter nodes. Cellular network communications module2256 performs operations supporting cellular network communications.

Base station 2212 includes a beacon transmission module 2213. Beaconsignal transmission module 2213 transmits beacon signals used forcommunications synchronization, identification, mode, and/or priorityinformation. In some embodiments, at least some of the beacon signalsare OFDM beacon signals including beacons signal bursts, each beaconsignal burst including at least one beacon symbol. Base station 2212 iscoupled to other network nodes e.g., other base station, routers, AAAnodes, home agent nodes, etc., and/or the Internet via link 2214. Basestation 2280 is coupled to other network nodes and/or the Internet vianetwork link 2281. Network links 2214, 2281 are, e.g., fiber optic linksand/or wired links.

Dotted line 2268 between wireless terminal 1A 2202 and base station 2212indicates that WT 1A 2202 can operate in a cellular communication modeand have a wireless communication link with a base station. Dotted line2266 between wireless terminal 1A 2202 and WT 2A 2206 2212 indicatesthat WT 1A 2202 and WT 2A 2206 can operate in a peer to peercommunications node and have a wireless communication link with anotherwireless terminal. The lines 2266 and 2268 have been indicated as dottedlines to indicate that WT 1A 2202 switches between the two modes.

Solid line 2274 between wireless terminal 1B 2204 and base station 2212indicates that WT 1B 2204 can operate in a cellular communication modeand have a wireless communication link with a base station. Solid line2272 between wireless terminal 1B 2204 and 2B 2206 2210 indicates thatWT 1B 2204 and WT 28 2210 can operate in a peer to peer communicationsmode and have a wireless communication link with another wirelessterminal. The lines 2272 and 2274 have been indicated as solid lines toindicate that WT 1B can maintain peer to peer and cellular networkcommunications sessions at the same time.

Line 2270 between wireless terminal 3 2208 and base station 2212indicates that WT 3 2208 can operate in a cellular communication modeand have a wireless communication link with a base station.

The various wireless terminals (2202, 2204, 2206, 2208 2210) includesubscriber plan identification information (2236, 2246, 2252, 2258,2264), respectively. In some embodiments, a set of wireless terminalscorrespond to a communications service subscriber who subscribes to afamily plan which supports multiple communications devices some of whichhave different capabilities. For example, in one embodiment, the set ofwireless terminals corresponding to the communications servicesubscriber who subscribes to a family plan includes WT1A 2202, WT 1B2204, WT 2A 2206, and WT 3 2208.

In some embodiments, the peer to peer communications modules (2218,2240, 2250, 2262) are OFDM communications modules. In some embodimentsthe cellular network communications modules (2230, 2242, 2256) are OFDMcommunications modules. In some embodiments, the peer to peercommunications modules (2218, 2240, 2250, 2262) are OFDM communicationsmodules, and the cellular network communications modules (2230, 2242,2256) are CDMA communications modules. In some embodiments, the peer topeer communications modules (2218, 2240, 2250, 2262) are OFDMcommunications modules, and the cellular network communications modules(2730, 2242, 2256) are GSM communications modules.

FIG. 32 is a drawing 3200 illustrating exemplary beacon burst timeposition hopping in accordance with various embodiments. Horizontal axis3202 represents time while vertical axis 3204 represents frequency,e.g., OFDM tones in a frequency band e.g., a non-infrastructurefrequency band being used for peer to peer communications. A wirelessterminal receives an external broadcast signal 3206 which the wirelessterminal uses a timing reference signal and upon which it bases itstiming structure. The external reference signal repeats as indicated bysignal 3206′. In some embodiments the timing reference point is derivedfrom information conveyed by the received broadcast signal. In thisexample, the peer to peer timing structure being used by the wirelessterminal includes a sequence of slots used for beacon signaling, eachtime slot is associated with a beacon signaling resource (slot 1 beaconsignaling resource 3208, slot 2 beacon signaling resource 3210, slot 3beacon signaling resource 3212. The slots repeat as indicated by slot 1beacon signaling resource 3208′. Each slot beacon signaling resourcerepresents a block of air link resources, e.g., OFDM tone-symbols.

The start of each beacon signaling resources slot (3208, 3210, 3212) isreferenced with respect a predetermined timing offset T1 3214, T2 3216,T3 3218). In some embodiments, the time duration of each beaconsignaling slot is the same. In some embodiments T2−T1=T3−T2.

Within each beacon signaling slot resource (3208, 3210, 3212), thewireless terminal transmits a beacon signal burst (3220, 3222, 3224)including at least one beacon symbol (3226, 3228, 3230), the beaconsymbol being a relatively high power symbol with respect to data symbolstransmitted by the wireless terminal. In this example, the time positionof the beacon signal burst with the beacon resource slot is hopped fromone slot to the next in accordance with a hopping function used by thewireless terminal. The hopping function varies the time of the beaconsignal burst from the start of the slot as indicated by different timeoffset values (T4 3234, Tr 3236, T6 3238) corresponding to (slot 1, slot2, slot 3), respectively. The hopping function determines the timeoffset as a function of a wireless terminal identifier, a useridentifier, and/or a priority level value. In some embodiments, otherinputs can be used by the hopping function, e.g., a received broadcastvalue associated with the spectrum, a received key, a value associatedwith a designated area, a value associated with a sector, etc.

In this example, the same tone is used by the wireless terminal for thebeacon symbol (3226, 3228, 3230, 3226′) of the beacon signal bursts(3220, 3220, 3224, 3220′), respectively, in slots resources (3208, 3210,3212, 3208′), respectively. Different wireless may, and sometimes do usea different tone for the beacon symbol.

FIG. 33 is a drawing 3300 illustrating exemplary beacon burst timeposition hopping and beacon symbol tone hoping in accordance withvarious embodiments. Horizontal axis 3302 represents time while verticalaxis 3304 represents frequency, e.g., OFDM tones in a frequency band,e.g., a non-infrastructure frequency band being used for peer to peercommunications. A wireless terminal receives an external broadcastsignal 3306 which the wireless terminal uses a timing reference signaland upon which it bases its timing structure. The external referencesignal repeats as indicated by signal 3306′. In some embodiments, thetiming reference point is derived from information conveyed by thereceived broadcast signal. In this example, the peer to peer timingstructure being used by the wireless terminal includes a sequence ofslots used for beacon signaling, each time slot is associated with abeacon signaling resource (slot 1 beacon signaling resource 3308, slot 2beacon signaling resource 3310, slot 3 beacon signaling resource 3312).The slots repeat as indicated by slot 1 beacon signaling resource 3308′.Each slot beacon signaling resource represents a block of air linkresources, e.g., OFDM tone-symbols.

The start of each beacon signaling resources slot (3308, 3310, 3312) isreferenced with respect a predetermined timing offset (T1 3314, T2 3316,T3 3318) from the external timing reference signal 3306. In someembodiments, the time duration of each beacon signaling slot is thesame. In some embodiments T2−T1=T3−T2.

Within each beacon signaling slot resource (3308, 3310, 3312), thewireless terminal transmits a beacon signal burst (3320, 3322, 3324)including at least one beacon symbol (3326, 3328, 3330), the beaconsymbol being a relatively high power symbol with respect to data symbolstransmitted by the wireless terminal. In this example, the time positionof the beacon signal burst with the beacon resource slot is hopped fromone slot to the next in accordance with a time hopping function used bythe wireless terminal. The hopping function varies the time of thebeacon signal burst from the start of the slot as indicated by differenttime offset values (T4 3334, T5 3336, T6 3338) corresponding to (slot 1slot 2, slot 3), respectively. The hopping function determines the timeoffset as a function of a wireless terminal identifier, a useridentifier, and/or a priority level value. In some embodiments, otherinputs can be used by the hopping function, e.g., a received broadcastvalue associated with the spectrum, a received key, a value associatedwith a designated area, a value associated with a sector, etc.

In this example, the tone of the beacon signal used by the wirelessterminal for the beacon symbol (3326, 3328, 3330) of the beacon signalbursts (3320, 3322, 3324), respectively, in slots resources (3308, 3310,3312), respectively, is also hopped from one slot to another inaccordance with a tone hopping function. Inputs to the tone hopingfunction include one or more of a wireless terminal identifier, a useridentifier, a priority level value, a received broadcast valueassociated with the spectrum, a received key, a value associated with adesignated area, and a value associated with a sector.

In this example, the next iteration of beacon signaling resource slot 13308′ has the beacon symbol 3326′ of beacon burst 3320′ placed in thesame OFDM tone-symbol position of the resource 3308′ as the beaconsymbol 3326 of beacon burst 3320 in resource 3308. In some embodiments,two separate hopping functions are used, one for beacon burst timehopping and the other for tone hopping. In some embodiments, the beaconburst time position hopping function and the tone hopping function havethe same sequence length. In some embodiments, the beacon burst timeposition hopping function and the tone hopping function have differentsequence lengths. For example, the two sequence lengths may be co-primewith each other. Alternatively, the ratio of one sequence length to theother sequence length may be an integer. In other embodiments, onehopping function is used for both beacon burst time hopping and tonehopping. Specifically, suppose that each beacon signaling resource slot3308, 3310, 3312 includes M symbol times and every symbol time includesN tones. Then, in each slot, the hopping function outputs a number,which uniquely identifies one specific tone at one specific symbol time.For example, the number can be 0, 1, . . . , M*N−1, where N and N arepositive integers. In some embodiments N is at least 100 and M is atleast 20, although in other embodiments, the values may be smaller.

FIG. 34 is a drawing 3400 illustrating exemplary coordinated timing in apeer to peer communications band in accordance with various embodiments.Drawing 3400 includes exemplary 1^(st) and 2^(nd) wireless terminal(3402, 3404), e.g., peer mobile nodes. Upper drawing portion 3401 isused to illustrate operations of wireless terminal 1 3402, while lowerdrawing portion 3403 is used to illustrate operations of wirelessterminal 2 3404. Horizontal axes 3406 represents time, while verticalaxes 3408 represents frequency, e.g., OFDM tones in the peer to peerfrequency band.

Both wireless terminals (3402, 3404) receive and use external broadcastsignal 3410 to obtain timing reference. Based on the timing referencesignal 3410, both wireless terminals (3402, 3404) recognize beaconsignaling resource slots 3412 and 3414. Wireless terminal 1 3402transmits a beacon signal burst 3416 including beacon symbol 3418 duringtime interval 3440, and beacon signal burst 3420 including beacon symbol3422 during time interval 3442. Wireless terminal 2 3404 is monitoringfor beacon symbols from other wireless terminals during time intervals3444, 3446, 3448, and 3450. Since time interval 3440 is with timeinterval 3446 wireless terminal 2 is able to detect the beacon symbol3418 from wireless terminal 1 3402. Since time interval 3442 is withintime interval 3450 wireless terminal 2 is able to detect the beaconsymbol 3422 from wireless terminal 1 3402.

Wireless terminal 2 3404 transmits a beacon signal burst 3424 includingbeacon symbol 3426 during time interval 3452, and beacon signal burst3428 including beacon symbol 3430 during time interval 3454. Wirelessterminal 1 3402 is monitoring for beacon symbols from other wirelessterminals during time intervals 3432, 3434, 3436, and 3438. Since timeinterval 3452 is within time interval 3432 wireless terminal 1 is ableto detect the beacon symbol 3426 from wireless terminal 2 3404. Sincetime interval 3454 is within time interval 3436 wireless terminal 1 isable to detect the beacon symbol 3430 from wireless terminal 2 3404.

In this example, both wireless terminals are able to detect beaconsignals from each other. The coordinated timing structure based on areference allows efficient operation and reduced power consumption,since modules within a wireless terminal can be powered down whentransmission and/or monitoring is not required, e.g., during silencemodes of operation.

Time hopping of the beacon burst, e.g., as a function of a wirelessterminal identifier, facilitates resolution of a problem where bothwireless terminal 1 and wireless terminal 2 should happen to transmit abeacon signal burst during one beacon signaling resource slot. In someembodiments, the beacon burst time hopping is structured so that atleast some beacon signal bursts transmitted by two peer wirelessterminals will be non-overlapping. In some embodiments, a wirelessterminal, occasionally, refrains from transmitting its beacon burstduring a beacon signaling resource and monitors for the full duration ofthe beacon signaling resource.

Additional embodiments, features and variations will now be discussed.

An infrastructure network usually includes a base station, whichprovides service to terminals in a given geographical area. In anexemplary embodiment, a base station of an infrastructure network uses afirst (infrastructure) spectrum band to provide service in ageographical area. Meanwhile, a second (non-infrastructure) spectrumband, which is different from the infrastructure spectrum band, is alsoavailable for the terminals in the area, e.g., to be used for an ad hocnetwork.

In accordance with various embodiments, in order to facilitate thetiming and/or frequency synchronization in the ad hoc network using thenon-infrastructure spectrum band, the infrastructure base stationtransmits a beacon signal.

In an exemplary embodiment, the base station transits the beacon signalin the infrastructure spectrum band. The desired common timing and/orfrequency reference to be used in the non-infrastructure spectrum bandcan be determined from the beacon signal. In addition, the base stationmay, and sometimes does, send system information about the frequencylocation of the non-infrastructure spectrum band and the type of serviceprovided in the non-infrastructure spectrum band, e.g., TDD (timedivision duplex) or ad hoc networking. The system information is sentusing the beacon signal and/or other broadcast control signals.

A wireless terminal first tunes to the infrastructure spectrum band todetect the beacon signal and derives the timing and/or frequencyreference to be used in the non-infrastructure spectrum band. Thewireless terminal further receives the system information from thebeacon and/or other broadcast control signals, ad determines thefrequency location of the non-infrastructure spectrum band, e.g.,carrier frequency. The wireless terminal tunes to the non-infrastructurespectrum band and uses the acquired timing and/or frequencysynchronization to start a communication link in the non-infrastructurespectrum band.

In another embodiment, the base station transmits the beacon signal thenon-infrastructure spectrum band, so that if the wireless terminaldirectly tunes to the non-infrastructure spectrum band, the wirelessterminal can derive the desired common timing and/or frequency referencefrom the beacon signal. In that embodiment, the base station may, andsometimes does, additionally transmit beacon and/or other broadcastcontrol signals in the infrastructure spectrum band as well as sendsystem information about the frequency location of the noninfrastructure spectrum band and the type of service provided in thenon-infrastructure spectrum band.

In yet another embodiment, in which the infrastructure spectrum band maynot exist, a special transmitter is set in a geographic area to transmita system beacon signal in each of the non-infrastructure spectrum bandsthat are available for use in the vicinity of the geographical area inwhich the special transmitter sits. In one embodiment, at a given time,the special transmitter transmits at most one beacon signal burst in aspectrum band. The special transmitter hops across each of the availablespectrum bands and transmits the beacon signal burst successively fromone spectrum band to another. A wireless terminal is to scan a candidatespectrum band to see whether a system beacon signal can be detected inthe candidate spectrum band. If a system beacon signal is detected, thenthe candidate spectrum band is available for use. Otherwise, thewireless terminal, in some embodiments, is not allowed to use thecandidate spectrum band, in which case the wireless terminal may have toscan another candidate spectrum band to find an available spectrum bandto use.

After the wireless terminal obtains the timing and/or frequencyreference from the beacon signal, the wireless terminal then tunes tothe non-infrastructure spectrum band. The wireless terminal, in someembodiments, starts to transmit its own user beacon signal in thenon-infrastructure spectrum band. Similar to the beacon signal sent bythe infrastructure base station, the user beacon signal also includes asequence of beacon signal burst in a spectrum band. However, the userbeacon signal, in some embodiments, is different from the beacon signalsent by the infrastructure base station in at least one of the followingways: the periodicity of the beacon signal bursts, the tone used in abeacon signal burst, and the hopping pattern of the tones used insuccessive beacon signal bursts. The wireless terminal may, andsometimes does, further listen to the non-infrastructure spectrum bandto detect the presence of a user beacon signal sent by another wirelessterminal. In some embodiments, the wireless terminal determinestransmission and/or detection of user beacon signals as a function ofthe timing and/or frequency reference from the beacon signal sent by theinfrastructure base station. When wireless terminals derive their timingand/or frequency reference from the same source e.g., the sameinfrastructure base station beacon signal it is easy for them to detecteach other's presence and to establish communication links.

In accordance with a feature of some exemplary embodiments, while awireless terminal is in a peer-to-peer communication session in thenon-infrastructure spectrum band, the wireless terminal may, andsometimes does, periodically suspend the session for a short time periodand tune to the infrastructure spectrum band, e.g., to check whetherthere is a page for the terminal. The time periods in which the wirelessterminal checks pages are, in some embodiments, pre-determined, so thatboth the wireless terminal and the base station can be synchronized onwhen a page should be delivered. In some embodiments, a set of wirelessterminals in the peer-to-peer communication sessions have a common timeperiod in which each of those wireless terminals suspend the sessions inthe non-infrastructure spectrum band and check pages in theinfrastructure spectrum band. Advantageously, this synchronization helpsreduce the wastage of session time in the peer-to-peer sessions.

In accordance with various embodiments, the infrastructure base stationalso provides service in the non-infrastructure spectrum band, e.g., toprovide peer-to-peer communication service and/or to provide TDDservice. The base station in some embodiments transmits the beaconsignal in such away that after the wireless terminal receives the beaconsignal the wireless terminal can predict the signal quality of a datasession if the wireless terminal is to establish a communication linkwith the base station. In one embodiment, the transmission power of thebeacon signal is the same for each of such base stations. In anotherembodiment, the data session e.g., at a given coding and modulationrate, is sent at a transmission power, which is a function of thetransmission power of the beacon signal. For example, the per minimumtransmission unit transmission power of the data session is a fixed dBamount, e.g., 10 dBs or 16 dBs, below the transmission power of thebeacon symbols of the beacon signal.

While described primarily in the context of an OFDM system, the methodsand apparatus of various embodiments are applicable to a wide range ofcommunications system including many non-OFDM, and/or many non-cellularsystems.

In various embodiments nodes described herein are implemented using oneor more modules to perform the steps corresponding to one or moremethods, for example, generating a beacon signal, transmitting a beaconsignal, receiving beacon signals, monitoring for beacon signals,recovering information from received beacon signals, determining atiming adjustment, implementing a timing adjustment, changing a mode ofoperation, initiating a communication session, etc. In some embodimentsvarious features are implemented using modules. Such modules may beimplemented using software, hardware or a combination of software andhardware. Many of the above described methods or method steps can beimplemented using machine executable instructions, such as software,,included in a machine readable medium such as a memory device, e.g.,RAM, floppy disk, etc. to control a machine, e.g., general purposecomputer with or without additional hardware, to implement all orportions of the above described methods, e.g., in one or more nodes.Accordingly, among other things, various embodiments are directed to amachine-readable medium including machine executable instructions forcausing a machine, e.g., processor and associated hardware, to performone or more of the steps of the above-described method(s).

Numerous additional variations on the methods and apparatus describedabove will be apparent to those skilled in the art in view of the abovedescriptions. Such variations are to be considered within scope. Themethods and apparatus of various embodiments may be, and in variousembodiments are, used with CDMA, orthogonal frequency divisionmultiplexing (OFDM), and/or various other types of communicationstechniques which may be used to provide wireless communications linksbetween access nodes and mobile nodes. In some embodiments the accessnodes are implemented as base stations which establish communicationslinks with mobile nodes using OFDM and/or CDMA. In various embodimentsthe mobile nodes are implemented as notebook computers, personal dataassistants (PDAs), or other portable devices includingreceiver/transmitter circuits and logic and/or routines, forimplementing the methods of various embodiments.

1. A method of operating a wireless device, the method comprising:determining from a first broadcast signal received from a base stationthat a frequency band corresponding to said base station is being usedfor peer to peer communications; determining from a second broadcastsignal received from the base station that said frequency band has beenchanged to being used as a cellular frequency band; and in response todetermining that the frequency band is being used as a cellularfrequency band reducing transmission power.
 2. The method of claim 1,wherein reducing transmission power includes a reduction in transmissionpower by at least 10 dBs.
 3. The method of claim 1, wherein reducingtransmission power includes ceasing to transmit.
 4. The method of claim1, further comprising: in response to determining that the frequencyband is being used as a cellular frequency band, terminating an ongoingpeer to peer communications session.
 5. The method of claim 1, furthercomprising: in response to determining that the frequency band is beingused as a cellular frequency band, putting an ongoing peer to peercommunications session into a hold state.
 6. The method of claim 1,further comprising: determining from a third broadcast signal receivedfrom said base station that said frequency band has been changed tobeing used for peer to peer cone communications.
 7. The method of claim6, further comprising: switching a peer to peer communications sessionwhich was in a hold state to an active state in response to said thirdbroadcast signal.
 8. A wireless communications device which supportspeer to peer communications, comprising: a receiver for receivingsignals including broadcast signals; a transmitter for transmitting userdata as part of a peer to peer communications session, a modedetermination module for determining based on received broadcast signalsa mode of communications band operation, the mode of communications bandoperation being a mode of operation in which said frequency band is tobe used at a point in time, the determined mode of communication bandoperation being one of a plurality of frequency band modes including atleast a cellular communications mode and a first peer to peercommunications mode; and a mode control module for controlling wirelesscommunications device operation as a function of at least one of a modedetermination and a change in a determined mode of communications bandoperation, said mode control module controlling the transmitter toreduce transmission power in response to determining that the frequencyband is to be used as a cellular frequency band.
 9. The wirelesscommunications device of claim 8, wherein reducing transmission powerincludes reducing transmission power by at least 10 dBs.
 10. Thewireless communications device of claim 8, wherein reducing transmissionpower includes ceasing to transmit.
 11. The wireless communicationsdevice of claim 8, further comprising: a peer to peer communicationssession termination module for terminating a peer to peer communicationssession in response to a determination that the frequency band is beingused as a cellular frequency band.
 12. The wireless communicationsdevice of claim 8, further comprising: a session hold module for puttingan ongoing peer to peer communications session into a hold state inresponse to a determination that the frequency band is being used as acellular frequency band.
 13. The wireless communications device of claim12, further comprising: a peer to peer communications sessionreestablishment module for transitioning a peer to peer communicationssession from a hold state to an active state in response to adetermination that said frequency band is to be used for peer to peercommunications.
 14. The wireless communications device of claim 8,wherein said mode control module supports first and second peer to peermodes of operation, said second peer to peer mode of operation being areduced power level mode of operation in which said wirelesscommunications device uses a lower maximum transmission power level forthe transmission of user data than is used during said first mode ofpeer to peer operation.
 15. The wireless communication device of claim14, further comprising: memory storing information indicating a firstmaximum transmission power level to be used during said first mode ofpeer to peer communications operation and a second maximum transmissionpower level to be used during said second mode of peer to peercommunications operation, said second maximum transmission power levelbeing lower than said first maximum transmission power level.
 16. Thewireless communications device of claim 14 wherein said wirelesscommunications device supports peer to peer communications but does notsupport a cellular mode of operation.
 17. A wireless communicationsdevice which supports peer to peer communications, comprising: receivermeans for receiving signals including broadcast signals; transmittermeans for transmitting user data as part of a peer to peercommunications session, mode determination means for determining basedon received broadcast signals a mode of communications band operation,the mode of communications band operation being a mode of operation inwhich said frequency band is to be used at a point in tine, thedetermined mode of communication band operation being one of a pluralityof frequency band modes including at least a cellular communicationsmode and a first peer to peer communications mode; and mode controlmeans for controlling wireless communications device operation as afunction of at least one of a mode determination and a change in adetermined mode of communications band operation, said mode controlmeans controlling the transmitter to reduce transmission power inresponse to determining that the frequency band is being used as acellular frequency band.
 18. The wireless communications device of claim17, further comprising: peer to peer communications session terminationmeans for terminating a peer to peer communications session in responseto a determination that the frequency band is being used as a cellularfrequency band.
 19. The wireless communications device of claim 17,further comprising: session hold means for putting an ongoing peer topeer communications session into a hold state in response to adetermination that the frequency band is being used as a cellularfrequency band.
 20. The wireless communications device of claim 19,further comprising: peer to peer communications session reestablishmentmeans for transitioning a peer to peer communications session from ahold state to an active state in response to a determination that saidfrequency band is to be used for peer to peer communications.
 21. Thewireless communications device of claim 17, wherein said mode controlmeans supports first and second peer to peer modes of operation, saidsecond peer to peer mode of operation being a reduced power level modeof operation in which said wireless communications device uses a lowermaximum transmission power level for the transmission of user data thanis used during said first mode of peer to peer operation.
 22. Thewireless communication device of claim 21, further comprising: memorymeans storing information indicating a first maximum transmission powerlevel to be used during said first mode of peer to peer communicationsoperation and a second maximum transmission power level to be usedduring said second mode of peer to peer communications operation, saidsecond maximum transmission power level being lower than said firstmaximum transmission power level.
 23. A computer readable mediumembodying machine executable instructions for controlling a wirelessdevice to implement a method, the method comprising: determining from afirst broadcast signal received from a base station that a frequencyband corresponding to said base station is being used for peer to peercommunications; determining from a second broadcast signal received fromthe base station that said frequency band has been changed to being usedas a cellular frequency band; and in response to determining that thefrequency band is being used as a cellular frequency band reducingtransmission power.
 24. The computer readable medium of claim 23,wherein reducing transmission power includes ceasing to transmit. 25.The computer readable medium of claim 23, further embodying machineexecutable instructions for: in response to determining that thefrequency band is being used as a cellular frequency band, terminatingan ongoing peer to peer communications session.
 26. The computerreadable medium of claim 23, further embodying machine executableinstructions for: in response to determining that the frequency band isbeing used as a cellular frequency band, putting an ongoing peer to peercommunications session into a hold state.
 27. The computer readablemedium of claim 23, further embodying machine executable instructionsfor: determining from a third broadcast signal received from said basestation that said frequency band has been changed to being used for peerto peer communications.
 28. The computer readable medium of claim 27,further embodying machine executable instructions for: switching a peerto peer communications session which was in a hold state to an activestate in response to said third broadcast signal.
 29. An apparatuscomprising: a wireless communications device processor configured to:receive signals including broadcast signals; transmit user data as partof a peer to peer communications session, determine based on receivedbroadcast, signals a mode of communications band operation, the mode ofcommunications band operation being a mode of operation in which saidfrequency band is to be used at a point in time, the determined mode ofcommunication band operation being one of a plurality of frequency bandmodes including at least a cellular communications mode and a first peerto peer communications mode; and control apparatus operation as afunction of at least one of a mode determination and a change in adetermined mode of communications band operation, said wirelesscommunications device processor controlling the apparatus to reducetransmission power in response to determining that the frequency band isbeing used as a cellular frequency band.
 30. The apparatus of claim 29,wherein said wireless communications device processor is furtherconfigured to: terminate a peer to peer communications session inresponse to a determination that the frequency band is being used as acellular frequency band.
 31. The apparatus of claim 29, wherein saidwireless communications device processor is further configured to: putan ongoing peer to peer communications session into a hold state inresponse to a determination that the frequency band is being used as acellular frequency band.
 32. The apparatus of claim 31, wherein saidwireless communications device processor is further configured to:transition a peer to peer communications session from a hold state to anactive state in response to a determination that said frequency band isto be used for peer to peer communications.
 33. The apparatus of claim29, wherein said apparatus supports first and second peer to peer modesof operation said second peer to peer mode of operation being a reducedpower level mode of operation in which said apparatus uses a lowermaximum transmission power level for the transmission of user data thanis used during said first mode of peer to peer operation.
 34. Theapparatus of claim 33, wherein said wireless communications deviceprocessor is further configured to: indicate a first maximumtransmission power level to be used during said first mode of peer topeer communications operation and a second maximum transmission powerlevel to be used during said second mode of peer to peer communicationsoperation, said second maximum transmission power level being lower thansaid first maximum transmission power level.